Wikipedia talk:WikiProject Mathematics/Archive/2021

Jan 2021

Reliability of tertiary sources such as of Encyclopedia of Mathematics

At Function (mathematics) § Injective, surjective and bijective functions, while getting some citations into this previously {{unreferenced section}}, I replaced a statement that a function is injective if and only if the preimage of each element of its codomain contains at most one element with a statement that a function is injective if and only if the preimage of each element of its range contains exactly one element (Special:Diff/999090776/999284001), because the latter statement (and not the former) appears in what I thought seemed like a convenient source, the "Function" article in the Encyclopedia of Mathematics, which WP:WikiProject Mathematics/Reference resources says [s]hould be regarded as a highly reliable source.

D.Lazard, when you reversed this change, saying EOM os a WP:tertiary source and therefore is not considered as a WP:reliable source in such a case (Special:Diff/999286540), what did you mean? I looked through the policy and guideline you linked, but, as far as I see, neither mentions any case in which being a tertiary source makes a source unreliable (unless the source is Wikipedia).

(This seems like more of a general matter than one specific to Function (mathematics), so I hope I may ask the question here rather than at Talk:Function (mathematics).)

—2d37 (talk) 13:40, 9 January 2021 (UTC)

WP:PSTS: Wikipedia articles should be based on reliable, published secondary sources and, to a lesser extent, on tertiary sources and primary sources.

WP:TERTIARY: Policy: Reliable tertiary sources can be helpful in providing broad summaries of topics that involve many primary and secondary sources, and may be helpful in evaluating due weight, especially when primary or secondary sources contradict each other.

So, the use of tertiary sources for specific technical definitions (as it is the case here) is not recommended, and not forbidden, although secondary sources and well known textbooks are preferred. Here there are many available textbooks, and the previous formulation is clearer than the formulation that is alleged to be closer than that of EOM. As both formulations are mathematically equivalent, and one may be confusing, we must keep the clearer one. If a citation would be needed, we would have to find a textbook that uses a closer formulation. However, as a sourced definition has been given in the preceding sentence, and the equivalence of the two formulations must be very easy for every body who understand them, WP:CALC applies, and I agree with your last edit removing EOM reference. D.Lazard (talk) 16:26, 9 January 2021 (UTC)

Facet theory

Can people here contribute to dealing with the issues raised by the maintenance tags atop the article titled Facet theory? Michael Hardy (talk) 17:54, 12 January 2021 (UTC)

This does not look like mathematics to me. JRSpriggs (talk) 21:29, 12 January 2021 (UTC)

It looks unfixable to me. XOR'easter (talk) 23:04, 12 January 2021 (UTC)

This appears to also have the same issues (with the same creator and topic for the most part) as Guttman scale. Both need a lot of work. — MarkH₂₁^talk 04:47, 13 January 2021 (UTC)

Delete "intersection" page?

Hello! I believe we should delete/merge the current intersection page. It should turn into a disambiguation page between intersection (set theory) and intersection (Euclidean geometry).

As it stands, I don't think a "general" intersection page is useful or necessary.

To my understanding, something is either a geometric intersection (so can go to intersection (Euclidean geometry)) or a set theory intersection (and can go to intersection (set theory)). Or maybe someone is looking for intersection theory. I think Intersection should turn into a disambiguation page. Otherwise, what should the "broad" page for intersection be? IMO all it would be is a description of Euclidean or set theory intersections. I don't know what reliable independent sources we could cite that give a broad explanation of both and more.

What do you think? Should we keep intersection? If so, what should we put there? Turn it into a disambiguation page?

I also started a discussion on the intersection (set theory) page.

I think it should be noted that:

• intersection is a start-quality page
• intersection (set theory) is a C-class page
• intersection (Euclidean geometry) is a C-class page

And if it is agreed not to change anything, at the very least I think intersection (set theory) needs a hat possibly directing to intersection (Euclidean geometry) or Intersection (disambiguation) and visa versa IllQuill (talk) 06:28, 16 January 2021 (UTC)

I agree that things must change, but I disagree with the proposed changes. IMO, the three article must be merged into a single article called intersection or intersection (mathematics). In fact, in modern mathematics, intersections are almost alway set-theoretical intersections. The only case where intersections are not set-theoretic, are the versions of incidence geometry where a line is not the set of its points. This is very marginal and could be treated in a section "In incidence geometry". This section could be rather short and shoud mainly explain that the two concepts of intersection are essentially the same even if they differ formally. D.Lazard (talk) 12:05, 16 January 2021 (UTC)

While that may be true conceptually, I think there's a very big difference in the set theoretic and geometric article perspectives: the latter is presenting methods for determining the set of points of intersection, hence equations of lines and curves, vectors, etc. The readership of the two articles themselves will also likely have different backgrounds and concerns. Incidentally, Intersection (set theory) as-is nicely complements the article Union (set theory). NeilOnWiki (talk) 14:07, 16 January 2021 (UTC)

Having one article called Intersection (mathematics) makes the most sense to me. It's the simple approach, and I like simple. Too often, we have lots of little articles that each carry a piece of a topic, and the pieces might overlap, telling the same story with contradictory notations — the inevitable consequence of editors independently adding what they feel like when and where they feel like it without agreeing on a curriculum first. So, every now and then we have to come through and reorganize. Such is life on a wiki! There's nothing wrong with having multiple perspectives in one article, particularly when displaying those perspectives together allows them to illuminate each other. Intersection (set theory) can always redirect to the proper section of the merged article. XOR'easter (talk) 17:03, 16 January 2021 (UTC)

I very much agree the general observation that "Too often, we have lots of little articles that each carry a piece of a topic, and the pieces might overlap, telling the same story with contradictory notations ... So, every now and then we have to come through and reorganize." But, in this particular case, Intersection (set theory) and Intersection (Euclidean geometry) are about very different aspects with no obvious overlap in content beyond the word intersection. The content in the geometry one is mainly vector algebra and solving simultaneous equations. These are applied mathematical techniques where a knowledge of set theory is irrelevant: eg. there's no mention of the word set even when any equation has multiple solutions, nor is there a need to. NeilOnWiki (talk) 19:32, 16 January 2021 (UTC)

I agree with D.Lazard and XOR'easter that we should rename the page Intersection (set theory) as Intersection (mathematics) and include the page Intersection (Euclidean geometry) in it. The overlap is not just in the use of the word "intersection"; there is just one notion of intersection here and it is applied in different areas of mathematics. What is the meaning of "intersection" in Euclidean geometry, if not the notion of intersection that is used throughout mathematics? If you disagree with combining the pages, do you think we should also have separate pages for Intersection (group theory) and Intersection (linear algebra) and ..., with one disambiguation page to rule them all, given that the methods for computing intersections in the different areas of mathematics may be different? To me, having all those separate pages would seem ridiculous. Ebony Jackson (talk) 21:15, 16 January 2021 (UTC)

It is possible to treat geometric lines as first-class objects that are not merely sets of points, and to define intersections of lines as an operation that is not merely intersection of sets of points. But it is not necessary to do so, and I don't see the point in doing so in our main intersection article. I agree that geometric intersections should be covered there, as a special case of set-theoretic intersections. —David Eppstein (talk) 21:38, 16 January 2021 (UTC)

Just chiming in to say that intersections in Algebraic Geometry and very much not set-theoretic, and a great deal of effort in intersection theory is made to understand them in terms of the more intuitive Euclidean intersection picture. This may be relevant when writing/updating the intersection article. Tazerenix (talk) 22:17, 16 January 2021 (UTC)

@David Eppstein: Yes, that is possible. If that is to be mentioned, perhaps it could be done in a "Variants" section of the page (or omitted from this page entirely, as you suggest).

@Tazerenix: Well, most of the time in algebraic geometry when one speaks of the intersection of two varieties, one does mean the intersection of the sets. Even if one is thinking scheme-theoretically, the underlying set is the set-theoretic intersection, and also the functor of points of the scheme-theoretic intersection is the functor whose values are the (set-theoretic) intersections of the values of the functor of points of the two subschemes being intersected. I suppose that you are thinking of the more sophisticated but less common kind of intersection, when one is working in the Chow group or the like, when the intersections are not proper. Anyway, sorry for going off-topic! This shouldn't affect the outcome of the merging discussion. Ebony Jackson (talk) 01:50, 17 January 2021 (UTC)

There are other geometrical aspects of intersections that don't fall into Euclidean Geometry. When studying Immersion (mathematics) the set of self-intersections of the map is of interest, but there is no requirement for either the source or target to be Euclidean. This would point to a wider intersection (mathematics) article.--Salix alba (talk): 06:55, 17 January 2021 (UTC)

Yes, the title does raise a few questions. Looking at its sources, I vaguely wonder if it should have been named Intersection (Computational geometry). But more fundamentally I wonder if we're concentrating too much on rarefied mathematical questions here and need to think more broadly about the encyclopaedia and its users. There's already a more general Intersection (disambiguation) page so in answer to the original question I'm unsure if we'd need a specifically mathematical one. As may be obvious, I'm very much against merging Intersection (set theory) into Intersection (mathematics) — which currently feels a bit of a lonely position. We need (I think) to consider what role is played by each article in disseminating mathematical information, what kind of readership will benefit from it, their background and prior knowledge, their aims and motivation. What's the role of Intersection (set theory)? It looks to me like it's there to explain a concept in (mostly naive) set theory at a fairly introductory level that's accessible to a wide readership. It has issues (not least in nullary intersection), but seems a fairly coherent, reasonably well-defined page if seen in that light, and one which nicely complements the Union (set theory) article. My fear is that we're proposing to turn it into something less accessible and less valuable if we try to merge it into a catch-all page in the way we're arguing. NeilOnWiki (talk) 09:38, 18 January 2021 (UTC)

+1 re: accessibility. --JBL (talk) 14:31, 18 January 2021 (UTC)

Yes, accessibility is important. I think accessibility and merging are not incompatible. An Intersection (mathematics) article could start with an elementary discussion of intersection of sets, and then later sections could mention how intersections in elementary geometry are calculated. If more advanced topics such as "scheme-theoretic intersection" are mentioned at all (and it's not clear that they should be), then they should appear only as remarks towards the end of the article. Ebony Jackson (talk) 17:23, 18 January 2021 (UTC)

Wikipedia:WikiProject Physics/Contest

Over at WT:PHYS, we decided to try a bit of an article improvement drive. As there might be an overlap of interest, I figured I'd also post a notice here. XOR'easter (talk) 16:55, 18 January 2021 (UTC)

I think that complex analysis is applicable to this contest. This page points out that there is a lack of explanation from a physics perspective, and this competition may improve it. However, since this competition is focused on physics, the improvement evaluated will be from the perspective of physics, which may complicate the evaluation. Page views are 16,786. --SilverMatsu (talk) 05:12, 19 January 2021 (UTC)

I'm going to change the page name of Hartogs's Theorem

I'm thinking of moving to Hartogs's theorem on separate holomorphicity. Also, looking at Talk:Hartogs's theorem, it seems that the maths rating template is not used. --SilverMatsu (talk) 11:52, 20 January 2021 (UTC)

About the rating template, anyone (e.g., you) is free to add it at any time. If you do move the article (I don't personally have an opinion), the page Hartogs's theorem should presumably be converted into a disambiguation page, pointing at the various targets currently in the note at the top of Hartogs's theorem. --JBL (talk) 13:43, 20 January 2021 (UTC)

I have fixed the hatnote of the article for using a standard format and removing a duplicate link. So, there are only two other links. As the theorem on infinite ordinals is clearly not a primary topic, there are only two candidates for being a primary topic. As these two Hartogs's theorems belong to the same theory (of holomorphic functions of several variables), the primary topic is certainly clear for the specialists. So, per WP:ONEOTHER a dab page seems unneeded.

I have no opinion on the move, but if it is done, the hatnote {{about}} must be replaced by a template {{redirect}}. D.Lazard (talk) 14:48, 20 January 2021 (UTC)

Huh? How is it "clear" that the ordinal theorem is "not a primary topic"? I don't think that's clear at all. --Trovatore (talk) 17:38, 20 January 2021 (UTC)

It is clear because of the size of the interested audience: complex analysis and these Hartogs's theorems are used in many areas of mathematics and physics, while, as far as I know, the properties of transfinite ordinals that are considered here are rarely used outside advanced set theory. D.Lazard (talk) 18:14, 20 January 2021 (UTC)

It's a really pretty, simple, and fundamental construction, from the early days of set theory. Everyone should really know it. The complex-analysis result is more a technical thing from deeper in the bowels of the subject.

That said, it's probably true that hardly anyone refers to the existence of the Hartogs number as "Hartogs' theorem". --Trovatore (talk) 19:17, 20 January 2021 (UTC)

Thank you for improving Hartogs's theorem. I checked the page that links to Hartogs's theorem, but it seems a bit confusing. Looking at the Friedrich Hartogs page, it seems that it is linked to the Hartogs number by writing Hartogs's theorem. Even for several complex variables, the link that explains that the continuity of the condition that the function becomes holomorphic can be derived from the separate holomorphicity was previously the Hartogs extension theorem, and the name was confused. This was the reason for trying to clarify this name.--SilverMatsu (talk) 06:04, 21 January 2021 (UTC)

@Kpgjhpjm: Thank you for the message. Please check out the discussion here.--SilverMatsu (talk) 07:14, 21 January 2021 (UTC)

@SilverMatsu:, Thanks for the ping , You may convert the page into a dab page as mentioned above. Kpgjhpjm 07:34, 21 January 2021 (UTC)

About the name of X-Pseudoconvex

There are multiple definitions for the domain called pseudoconvex, and each name seems to be called differently depending on the person, but at Wikipedia, I wanted to discuss how to call it. Perhaps the early treatises were written in French (although one option is to choose a name that is commonly used in English), and on this page I found a user whose native language is French. I thought I would consult on this page. thanks!--SilverMatsu (talk) 23:20, 10 January 2021 (UTC)

Do you mean to say domain of holomorphy, (open) pseudoconvex subset and Stein manifolds are all the same thing so Wikipedia should pick one term to refer to them all? It is usually a bad idea to try to mess with terminology in Wikipedia; since, for one thing, there are many anonymous editors who edit math articles and we cannot expect them to be aware of some terminological insider convention. It is desirable and is quite achievable to use some consistency within a single article, though. -- Taku (talk) 00:08, 11 January 2021 (UTC)

Thank you for your reply. In a narrower story, I would like to ask if the usage of the names p-pseudoconvex, Levi pseudoconvex, Strongly pseudoconvex, and Cartan pseudoconvex is popular(commonly). I'm not trying to define these in one way. Each of these definitions has its own advantages. These names are ambiguous to myself. thanks!--SilverMatsu (talk) 00:35, 11 January 2021 (UTC)

Ah, I see. Usually in Wikipedia, the best way to approach the problem like this is to pick and follow a standard and *recent* textbook on the subject. For example, in this case, we can follow Demailly, Complex Analytic and Differential Geometry. In Theorem 7.2. it is shown that various notions like strongly psuedoconvex or weakly psuedoconvex are equivalent and that equivalence is used to define the common notion "pseudoconvex". In Wikipedia, we can do the same; i.e., an open subset is pseudoconvex if it satisfies the following equivalent conditions are met. ..... For Levi pseudoconvex, you need (as I understand) a C_2 boundary so we can say if the boundary is C_2, pseudoconvexity can be characterized in the Levi form. (I'm happy to leave the matters to specialists (I am certainly not) but I am also happy to edit the article myself if needed). -- Taku (talk) 04:03, 11 January 2021 (UTC)

Thank you very much! It was very helpful.--SilverMatsu (talk) 06:54, 11 January 2021 (UTC)

By the way, on the wiki, typing \mathscr seems to give an error.--SilverMatsu (talk) 08:10, 11 January 2021 (UTC)

You can see what TeX math fonts are available at Wikipedia:LaTeX symbols#Fonts. There is \mathcal, but no \mathscr. —2d37 (talk) 11:04, 11 January 2021 (UTC)

Thank you for teaching me. I'll try.--SilverMatsu (talk) 11:09, 11 January 2021 (UTC)

Although it is a 1954 paper, I found a paper that can be used as a reference for the name of the pseudoconvex domain. See https://doi.org/10.2969/jmsj/00620177. With reference to this material, Levi Pseudoconvex can be called as it is, and Levi convex (Equivalent conditions 4) may be called Levi strongly-Pseudoconvex. It seems that it can be called strongly pseudoconvex or locally analytical convex, but if we use strong pseudoconvex for the pseudoconvex region defined using the Strictly plurisubharmonic function, or considering the relationship with the pseudoconvex, I'm thinking of calling it Levi strongly-Pseudoconvex. thanks! --SilverMatsu (talk) 07:03, 24 January 2021 (UTC)

I'm sorry I seemed to have misunderstood. Levi convex seems to have been convex to the analytical surface.--SilverMatsu (talk) 08:38, 25 January 2021 (UTC)

Help:MATH

I came to this page after a discussion with a new user who changed systematically html to latex, even for isolated variables. He referred to this help page, which was blatantly biased toward latex. Moreover, the page contained very technical details that was of no help for the normal users of this help page. So I have rewritten the beginning of this page.

The new version gives advices that are based on an implicit consensus that I have deduced from many discussions in this talk page. Please, review my version for improving it, and fixing it, if I have misunderstood something. D.Lazard (talk) 14:40, 25 January 2021 (UTC)

"Thagomizer Matroids"

This is extremely tangentially related to mathematics for which I apologise. "Thagomizer" is an informal term for the tail spikes of stegosaurian dinosaurs, originally coined in comic strip. I have nominated this article for deletion. Several support votes for the article being kept have advanced the naming of a mathematical concept entitled "Thagomizer matroids" (and to a lesser extent "Thagomiser graphs") after the term, which are associated with Kazhdan–Lusztig polynomials as evidence of notability. The term appears to have been coined in a 2017 article in Electronic Journal of Combinatorics. As a non-mathematician, the term seems like one of hundreds, perhaps thousands of minor mathematical terms used in the literature, and not really evidence of notability of the article. Can I have a second opinion on the prominence of this term? Thanks. Hemiauchenia (talk) 16:30, 25 January 2021 (UTC)

Two published math papers have used it. There's no secondary commentary on etymology in either paper. It's a cute joke, but this is not a good indicator of notability. --JBL (talk) 16:49, 25 January 2021 (UTC)

Properties of integers

Please could a number theorist(?) review recent additions by 109.106.227.16? There are a number of plausible claims which may be worth keeping but the text generally seems too detailed for its articles. Certes (talk) 21:28, 14 January 2021 (UTC)

@Certes: They appear wholly unreferenced and unnoteworthy. I couldn't find any references for these claims from a quick search either. — MarkH₂₁^talk 21:35, 14 January 2021 (UTC)

Is 2 the only prime cake number? It's the only one up to 10,000 but that's hardly a rigorous proof. This seems a simple enough conjecture to have a proof or counter-example or prize on offer, and I can find none of those. Certes (talk) 22:14, 14 January 2021 (UTC)

I have no idea! There isn't much literature on the topic, and I haven't found a reference for that fact either but I wouldn't be surprised if it's out there somewhere. — MarkH₂₁^talk 22:31, 14 January 2021 (UTC)

Oddly enough I'd searched for the cake proof in Yaglom & Yaglom, which you just cited for a different claim, but couldn't find anything relevant. Certes (talk) 22:37, 14 January 2021 (UTC)

Here's a quick and easy proof that just came to mind: $(n^{3}+5n+6)=(n+1)(n^{2}-n+6)$ is always divisible by 6, since $n^{2}-n+6$ is always even and is divisible by 3 when $n\not \equiv 2{\pmod {3}}$ while $n+1$ is divisible by 3 when $n\equiv 2{\pmod {3}}$. The two factors are also each larger than 6 when n > 5, so $C_{n}={\frac {n^{3}+5n+6}{6}}$ has two nontrivial integer factors for n > 5.

Technically, the above is OR. I don't think it's worth me putting this anywhere to circumvent that though. — MarkH₂₁^talk 22:52, 14 January 2021 (UTC)

Thanks; at least it's verifiable in the mathematical rather than the WP:V sense. I was halfway there but my maths is rusty. If we leave the {{cn}} then someone may find that in a book somewhere. Certes (talk) 23:01, 14 January 2021 (UTC)

Yaglom (Vol I, solution 45a) states that the differences are the 2D Lazy caterer's sequence (and uses the fact to derive the formula for the nth 3D cake number), so that may be sufficient proof of that assertion. Certes (talk) 00:13, 15 January 2021 (UTC)

Ah, thanks. Adding the citation now! — MarkH₂₁^talk 00:17, 15 January 2021 (UTC)

I've removed the additions from 37 and 89 again (and I'm sure the $16,000 will go to a good cause). Certes (talk) 20:02, 25 January 2021 (UTC)

about Plurisubharmonic function

I think it is correct that Oka defined the Plurisubharmonic function for the research of the pseudoconvex domain, but it seems to call it the pseudoconvex function. Seems to be called as fonction pseudoconvexe. See Oka, Kiyoshi (1942), "Sur les fonctions analytiques de plusieurs variables. VI. Domaines pseudoconvexes", Tohoku Mathematical Journal, First Series, 49: 15–52, ISSN 0040-8735, Zbl 0060.24006.　Need to annotate this? --SilverMatsu (talk) 05:44, 27 January 2021 (UTC)

So, I am not exactly knowledgable with the history of this area (even though Oka is prominent enough in Japan that his profile sometimes appear in a newspaper). But, speaking generally, it is always a good idea to give a historical note on the original terminology (so to help the readers going through old texts). -- Taku (talk) 04:37, 28 January 2021 (UTC)

Thank you for your reply. Apparently, it was also pointed out in Talk:Pseudoconvex function. I left a note on the page. I'm wondering whether to link the pseudoconvex function of convex analysis to the pseudoconvex function. The position to put the annotation may not be appropriate(I would like to put it outside the title ...). thanks!--SilverMatsu (talk) 10:18, 28 January 2021 (UTC)

I am not too sure if that makes sense or that's stretching the connection too much. As the lead of subharmonic notes nicely, there is certainly a sort of analogy between convexity and subharmonicity. On other hand, as far as I can tell, convex analysis and several complex variables tend to be fields with little interaction between the two (I am not saying that's good or bad). -- Taku (talk) 01:11, 31 January 2021 (UTC)

Definition of the limit of a function

In (ε, δ)-definition of limit, limit of a function and several other articles, the limit of a function is defined as

$$\lim _{x\to c}f(x)=L\iff (\forall \varepsilon >0,\,\exists \ \delta >0,\,\forall x\in D,\,0<|x-c|<\delta \ \Rightarrow \ |f(x)-L|<\varepsilon ).$$

Because of the condition $0<|x-c|,$ I call this definition the "punctured definition".

The definition that I have learnt more than 40 years ago, is the "unpunctured definition"

$\lim _{x\to c}f(x)=L\iff (\forall \varepsilon >0,\,\exists \ \delta >0,\,\forall x\in D,\,|x-c|<\delta \ \Rightarrow \ |f(x)-L|<\varepsilon ).$

I never remarked that there were two different definitions that are commonly given, before the recent discussion at Talk:Function of several real variables#Minor edit: Section on continuity and limit.

In French Wikipedia, it is the unpunctured definition that is given. In German Wikipedia, the punctured definition is given first, and later in the article the unpunctured definition is given in a section called (in German) "Newer definition". (The terms "punctured" and "unpunctured" are the translation of the German words that are used for comparing the definitions.)

I guess that the punctured definition is commonly used in US educational mathematics, while the unpunctured one is more commonly used in advanced mathematics. This needs verification.

I have no clear opinion which definition must be chosen for English Wikipedia, but whichever definition is kept, Wikipedia readers must be warned that both definitions are commonly used. As this implies to edit several articles, a discussion is needed here for fixing how we must proceed. D.Lazard (talk) 18:37, 25 November 2020 (UTC)

In my experience, the punctured definition is used universally in English. (But I am not an analyst, I cannot speak to what happens beyond the level of undergraduate education.) Both definitions are discussed in one of the articles, see Limit of a function#Deleted versus non-deleted limits where it is asserted (with citation) that punctured limits are "most popular". (Though it's not the issue here, I like "punctured" better than "deleted".) --JBL (talk) 18:43, 25 November 2020 (UTC)

The fact that the limit of a sequence/function can attain a value that is outside the original set of definition is a tremendously important fact at every level of real analysis. For example, how does one define the limit as $t\to \infty$ of a function $f:\mathbb {R} \to \mathbb {R}$ with the unpunctured definition of a limit? Mathematicians try their best not to treat infinity as a number, so with the punctured definition, it is straightforward. Many questions like this (compactness, closedness, the relationship between limits/continuity for sequences/functions) are much better understood if you remember from the beginning that limits can land outside the set you originally started with. I vote we use the punctured definition, and give an example such as the one above to explain pedagogically the difference between the two approaches in the article. Tazerenix (talk) 19:30, 25 November 2020 (UTC)

@Tazerenix: I think that's a different issue from the one here: if the point at which the limit is being taken is outside of the domain, then [D.Lazard's version of] the punctured and unpunctured definitions agree (see the universal quantifier $\forall x\in D$). The question here is rather whether (e.g.) the Kronecker delta function $\delta _{0,x}$ has a limit as $x\to 0$ or not. --JBL (talk) 19:38, 25 November 2020 (UTC)

Right. The punctured definition allows us to compute limits at removable singularities. Does the unpunctured definition essentially require the function to be continuous, or am I jumping the gun? Mgnbar (talk) 20:07, 25 November 2020 (UTC)

@Mgnbar: that's right, in the unpunctured definition, the condition "the limit exists at a point of the domain" means the same as "the function is continuous at that point". (That is the genesis of this discussion, see Talk:Function of several real variables -- it refers to Function_of_several_real_variables#Continuity_and_limit and in particular the sentence If a is in the interior of the domain, the limit exists if and only if the function is continuous at a in that section of the article.) --JBL (talk) 20:42, 25 November 2020 (UTC)

How is one supposed to discuss semi-continuity with the unpunctured definition? Ozob (talk) 16:12, 26 November 2020 (UTC)

@Ozob: Could you expand on what the issue is here? I was hoping someone better qualified than me would answer your question, but here's my understanding of why this may be a non-problem. Looking at the Semi-continuity article, the formal topological definition of upper semi-continuity at x₀ involving neighbourhood U isn't affected by switching between the punctured or unpunctured limit definitions, except possibly when f(x₀) = -∞. There's a lim sup formulation for metric spaces (hence for Rⁿ) which involves a limit, but lim sup for a function requires a one sided limit for ε>0 (so not punctured), where ε is the half-width of an interval about x₀. (Also, though probably irrelevant, the result is identical whether or not the sup is taken over a punctured or an unpunctured interval around x₀.) NeilOnWiki (talk) 15:30, 22 December 2020 (UTC)

@NeilOnWiki: Suppose that $f(z)=0$ for $z\neq 0$ and that $f(0)=1$. This function is upper semi-continuous, and the limit at $z=0$ exists (under the punctured definition). This kind of situation arises naturally, for example, in algebraic geometry (where $f$ is the fiber dimension of the blowup of the origin), but it is not even fully describable using the unpunctured definition.

My opinion is that the unpunctured definition is erroneous, and sources that use it are mistaken. I do not even see a reason for articles to discuss the unpunctured definition unless we can find sources stating that it is a common error. Ozob (talk) 16:02, 22 December 2020 (UTC)

Not sure about semicontinuity, but it would be good to pin down why the difference in definitions arises: eg. whether it's down to European vs. U.S. expectations; or recent trends; or if there's a compelling reason for choosing one definition rather than the other. Encyclopædia Britannica online uses the unpunctured version; as does my British-published Collins dictionary of Mathematics. But the Concise Oxford Dictionary of Mathematics (5 ed.) seems to favour the punctured version. Subjectively, the punctured version seems (to me) to introduce a condition that's irrelevant to the intuition that a function has a limit L at c if f(x) becomes more nearly equal to L as x moves increasingly close to c. Why delete c in the formal definition? It seems unnecessary. Under the unpunctured definition, if we need to exclude c (eg. at a singularity), then we can restrict the function domain accordingly. This, in effect, is what we do if we write $\lim _{\stackrel {x\to x_{0}}{x\neq x_{0}}}f(x)\to y$ (which we see in the Filters in topology article). This notation is redundant under the punctured definition, except for emphasis or disambiguation.

Interestingly, JBL's Limit of a function#Deleted versus non-deleted limits link observes that the unpunctured definition interacts more nicely with function composition (my wording). The source for this is several decades more recent (2015) than the multiple sources cited to support that the punctured definition is more popular (latest 1974). Looking at articles more widely in topology, it seemed to me that English Wikipedia is surprisingly consistent in preferring the punctured definition (generalised to open sets, neighbourhoods, nets, etc). The non-standard analysis topics may be less consistent, depending on whether or not an article considers 0 to be an infinitesimal (I'm fairly unconfident here).

Incidentally, the punctured definition vacuously implies (I think!) that if c is an isolated point, then any L in the codomain of f (and not just in the image of f) is a limit as x approaches c. The unique unpunctured limit is f(c). The latter seems less perverse — though it might just be that the example itself is fairly perverse. NeilOnWiki (talk) 20:46, 2 December 2020 (UTC)

I believe that at least in modern English sources, the punctured definition is used almost universally, at all levels of mathematics. Ebony Jackson (talk) 18:29, 5 December 2020 (UTC)

Yes, this is my experience as well. I find the "unpunctured definition" sort of bizarre, frankly. What is the point of taking a limit, if it has to actually be the value of the function at that point? It seems to be entirely redundant with the notion of continuity; it's not clear why you would need both. And it means that you can't, for example, write the definition of derivative as

$f'(x)=\lim _{h\rightarrow 0}{\frac {f(x+h)-f(x)}{h}}$

which is how it is usually presented in calculus classes. (I suppose you could quibble that $h=0$ is not in the natural domain of the right-hand side, but this strikes me as confusing and error-prone.) --Trovatore (talk) 00:14, 13 December 2020 (UTC)

@Trovatore: I think these are persuasive points. Even so, I'd like to stick up for the unpuncturists, as I think that, even if they're a minority, it's a mathematically valid position and one taken in at least some sources. I guess it'd be good to have an idea of how significant a minority they are.

On your first point, continuity isn't completely equivalent to the unpunctured limit existing (only when the point in question is in the function domain), so the unpunctured limit isn't "entirely redundant". To my mind, the unpunctured definition copes less bizarrely for Real valued functions on the Integers f: Z→R, where a puncturist could assert that 2x→0 as x→1 (remembering that x ∈ Z — admittedly I can't think why anyone would do this). These arguments may both be down partly to aesthetic preference.

It's a long time since I learnt calculus and I'm not a teacher. My impression is that any tutor using this definition makes resolutely clear in the preamble that h is non-zero, so there's no ambiguity over the domain. NeilOnWiki (talk) 15:23, 13 December 2020 (UTC)

Perhaps this is a matter of taste, but I find the punctured definition more appealing for functions $f\colon \mathbf {Z} \to \mathbf {R}$. This definition means that every real number is a limit of $f$ at every point. While ambiguity is not usually a desirable property, I think it is natural in vacuous situations like this. It is still the case that such an $f$ is continuous. Ozob (talk) 16:14, 22 December 2020 (UTC)

(←) Thanks, Ozob. Apologies for being so late replying. I agree this ambiguity is logically consistent, though it does also produce what seems like some odd results geometrically. For example, we now have a continuous f where there's a limit but not a unique one (even though R is a Hausdorff space). Hence, we may need to pause before writing that in general a Real-valued function f is continuous at c iff the limit exists and equals f(c), because we might have to choose our phrasing more carefully to account for non-uniqueness if there's a possibility that c is an isolated point (as happens with c ∈ Z above). Interestingly, the Net article has a definition of limit with a punctured flavour for a function from a metric space to a topological space, which does ensure uniqueness when the codomain is Hausdorff. It agrees with the punctured ε-δ definition when c is a cluster point (limit point), but not when c is isolated. Instead, in effect it avoids the vacuous condition for an isolated point and implies the limit either doesn't exist or uniquely equals f(c). (As far as I can tell, although it's not developed there, the obvious unpunctured counterpart would be fully consistent with the unpunctured ε-δ definition for both kinds of point.)

I found this a surprisingly interesting question, not least to see how this kind of Wikiepdia discussion is concluded. MOS:MATHS has a section on Mathematical conventions. Would it make sense to add an entry for Limit of a function there? I also wonder whether it might help future editors by adding a summary of some of the less obvious implications of the punctured definition (notably for function composition and isolated points), if this were put forward as the more popular approach. NeilOnWiki (talk) 14:21, 30 December 2020 (UTC)

Hi Everyone: In the absence of cries of "that's a terrible idea", I'm planning to make the edits to MOS:MATHS that I proposed in the previous paragraph, echoing the consensus here regarding the punctured version (and adding a pointer to this conversation on the MOS:MATHS Talk page). It strikes me that it would be a shame if the current conversation disappeared into the ether, especially considering D.Lazard's initial concerns over the plurality of articles and editors. It may take me a week or so to get round to it, so please stall me if my doing so seems inappropriate or somehow premature. NeilOnWiki (talk) 16:33, 13 January 2021 (UTC)

I'm sorry to raise a further question so late in the day, but in preparing for editing MOS:MATHS regarding the punctured definition, I've realised there's an additional question over which points c are permitted. Must c be a limit point of the domain D? And is the limit undefined if not (i.e. if it's an isolated point)?

Up until now, I'd tacitly assumed that it applied to any c in the closure of D (hence No to both preceding questions). But (ε, δ)-definition of limit § Precise statement for real-valued functions restricts c to being a limit point (likewise for metric spaces); and similarly in Limit of a function § More general subsets. Neither article says whether the limit is undefined (or defined differently) for isolated points; or if it extends to them unchanged. My guess is that we can indeed apply the punctured definition both to the limit points of D and its isolated points: it's just that authors may prefer not to lump them together because (as we've noted) the latter case would imply a condition which is satisfied vacuously and hence (generally) not uniquely. Can anyone here help clarify whether the generally accepted pre-conditions for the punctured definition really does exclude taking the limit at an isolated point? (Incidentally, there are implications on the relationship between limits and continuity of a function if so.) I'm not an analyst, and I don't have easy access to any definitive texts. Thanks. NeilOnWiki (talk) 16:37, 27 January 2021 (UTC)

THe definition without the $0<|x-c|$ condition seems strange to me. For a discontinuous function $f(x)={\begin{cases}1&{\text{for }}x=0\\0&{\text{otherwise}}\end{cases}}$ it would imply $f$ has no limit at $x=0$. --CiaPan (talk) 18:06, 27 January 2021 (UTC)

@CiaPan: I think you're in the majority in this. The question I had was about when you have points in the function domain which are "discontinuous" (what I meant by isolated), such as a function g: Z→R from the Integers to the Reals, e.g. g(n) = πⁿ. I originally thought that taking the limit was still well-defined for this case (though multi-valued, because you get a vacuous "for all" condition); but the Wikipedia articles I looked at seem to restrict the definition so you couldn't apply it to cases like this. I'd like to find out if this restriction really does hold and if the limit is therefore classed as undefined at c ∈ Z for a function on the Integers like g(n). NeilOnWiki (talk) 14:15, 28 January 2021 (UTC)

@NeilOnWiki: I have no idea whether defining a limit of a function at a separated (isolated) point of a domain makes any sense. The limit is a formalized way to express 'approaching to'. When $k\in D$ is an isolated point, the argument $x$ of a function $f$ can not 'approach' $k$. Then a function value $f(x)$ can not 'approach' $f(k)$, hence there is no need to define a limit of $f$ as $x\to k$. Additionally, we consider limits at boundary points of an open domain (e.g., $\lim _{x\to 0}{\frac {x}{x}}$, which is obviously 1); that will not apply to isolated points, either, because we have no value of a function anywhere 'close to' the isolated point. --CiaPan (talk) 17:29, 28 January 2021 (UTC)

A punctured definition seems like $\lim _{x\to c}\sup f(x)=L\ and\ \lim _{x\to c}\inf f(x)=L$, a non-punctured definition seems like $\lim _{x\to c}\max f(x)=L\ and\ \lim _{x\to c}\min f(x)=L$. When defining a function f for a real number, we often take a sequence of rational numbers $\{c_{n}\}_{n=1}^{\infty }$ that converges to the real number c.--SilverMatsu (talk) 01:28, 29 January 2021 (UTC)

To be fair, I think that if you have a continuous function on the Rationals, then you can still plug-in the non-punctured definition to extend it to the Reals, i.e. it still works for c ∉ D when c's a limit point not in D (so it isn't quite like max vs. sup). In answer to CiaPan (for which thanks): although I agree it jars with geometric sense, once you have a formal punctured definition like the one given by D.Lazard you can just mechanically work through the logic to test if a given f(x)→L as x→c. The formal reasoning goes through even when c is isolated, in which case it implies f(x)→L for any L. (It's a bit like the formal definition is saying "if you can get close to c, then f must get close to L", so if you can't then the requirement goes away, ie. gets satisfied vacuously.) This may seem odd, but I think it allows analysts to come up with an equivalence between continuity and limits: viz. a general function f: D→R is continuous at c iff the limit exists there and f(x)→f(c) as x→c. This would work formally even when D = Z, in which case we'd have continuity at every c ∈ Z in line with what a topologist would say. But our (ε, δ)-definition of limit article seems very careful to exclude taking the limit at an isolated point. I don't really see why it does that (unless it's established practice in analysis), as it seems unnecessary and weakens the continuity/limits equivalence. NeilOnWiki (talk) 16:49, 29 January 2021 (UTC)

Thank you for teaching me. What do you think of function that is continuous everywhere but differentiable nowhere?--SilverMatsu (talk) 01:14, 30 January 2021 (UTC)

I'm really not trying to teach anyone; just trying to understand whether it's right for our articles to restrict the punctured definition to limit points (cluster points). Thanks for the link to the Weierstrass function, which I'd not seen before. NeilOnWiki (talk) 17:13, 31 January 2021 (UTC)

Draft:Third Vote could use a bit of a review

Nikogosyan has written a draft for the third vote election method. While I'm normally pretty mathematically inclined, and have an interest in electoral methods, I think this draft is pretty far over my head. If there's anyone who's able to give a general "OK" that it should be ready for mainspace, that would be very helpful—my main concern is that the draft might be crossing the line of being too close to an essay, but I'm not sure to what extent that policy applies in a mathematical article. Perryprog (talk) 18:52, 31 January 2021 (UTC)

I don't think the extent to which this is mathematical is relevant. (I also don't think the complication of this method has much to do with mathematics.) I agree with you that it is very essay-like. --JBL (talk) 19:05, 31 January 2021 (UTC)

Perhaps you're right; I guess I didn't read the prose too in-depth and just got scared by the intimidating wikitables :). WP:TECHNICAL#Rules of thumb could also be of some use here, I think. Perryprog (talk) 19:21, 31 January 2021 (UTC)

Yes, the tables are intimidating and also poorly placed: each of them comes before any text that would allow the reader to make sense of it. Particularly egregious are the last two lines in Table 1 (Popularity+ and Parliament faction size+), which are not explained until the subsection "Faction equalization effect" of the Criticism section, practically at the end of the article. --JBL (talk) 19:28, 31 January 2021 (UTC)

Feb 2021

math display=block

MOS:MATH says that <math display=block> must be used instead of a colon for displaying a formula. Having testing this, it appears that this provides a bad result: the vertical space before and after the formula is much larger than with a colon. This is definitely confusing as suggesting that the formula is a paragraph by itself, even when the formula is in the middle of a sentence. So, I think that this recommendation must be removed until this bug will be fixed. (I do not know how to submit a bug report for such a case, and submitting a bug report would be more efficient if supported by a consensus.)

By the way, if one want that editors use <math display=block>, this must be added to "Math and logic" menu. D.Lazard (talk) 11:47, 2 February 2021 (UTC)

I agree the spaces give a wrong impression (and also look ugly). Jakob.scholbach (talk) 12:19, 2 February 2021 (UTC)

Can you give an example where you think it looks bad? I have used it in various articles, and have never noticed such an issue. —JBL (talk) 12:46, 2 February 2021 (UTC)

I wonder if there is some confusion here in which someone is mistaking <math display=block> for <blockquote>. I would agree that the latter puts too much space above and below the displayed line. Michael Hardy (talk) 02:18, 4 February 2021 (UTC)

I wonder if someone is comparing <math display=block> to colon-math with blank lines above and below the math, and not noticing that with <math display=block> it makes a difference whether there is a paragraph break before or after the display. If you want to use <math display=block> within a paragraph of text, and make it look like it is a displayed math block within that paragraph, you need to not format it as its own separate paragraph. —David Eppstein (talk) 04:24, 4 February 2021 (UTC)

Trying out all the options. A blank line before a colon-math

$E=mc^{2}$

Using a blank line after colon-math

$E=mc^{2}$

Using blank line before and after colon-math

$E=mc^{2}$

Using blank line before display=block

$$E=mc^{2}$$

Using blank line after display=block

$$E=mc^{2}$$

Using blank line before and after display=block

$$E=mc^{2}$$

On my machine, google chrome on a Chromebook, and MathML with SVG or PNG fallback, I can see no difference in the indentation of any of these. There might be a bug here but we would need to see a reproducible example. p.s. When quoting code examples its good to wrap them in <nowiki>...</nowiki> tags to prevent the parser from trying to interpret the tag. The {{tag}} template is handy for this as well. --Salix alba (talk): 06:55, 4 February 2021 (UTC)

• It's not the indentation but the vertical spacing around them. And I don't think it's actually a bug, but more a level of control that's not available with the colons. For me, Chrome on OS X, the blank lines are visible as extra space in the math display block versions, but not the colon math versions. Did you also notice that if you place
  $${\text{an equation}}$$
  in the middle of an bulleted item list, it is properly double-indented, and your bulleted paragraph continues with the correct indentation afterwards? —David Eppstein (talk) 07:06, 4 February 2021 (UTC)

Here is an example taken from the lead of Change of basis that I have recently edited, firstly with a colon,

$\mathbf {x} _{\mathrm {old} }=\mathbf {A} \,\mathbf {x} _{\mathrm {new} },$

followed with the same with "display = block"

$$\mathbf {x} _{\mathrm {old} }=\mathbf {A} \,\mathbf {x} _{\mathrm {new} },$$

In both case, there are no blank lines in the source before or after the displayed formula. As the formula is inside a sentence, the extra vertical space before the formula with "display=block" is definitively a bug. Surprisingly, there is no visible extra vertical space after the formula, although there was one when I edited the article (smaller than the extra space before the formula). Possibly, the implementation of "display=block" has been modified since the opening of this thread. D.Lazard (talk) 08:25, 4 February 2021 (UTC)

It looks like the spacing in the second example is controlled by the style sheets in MediaWiki:Common.css. In particular

/* Make <math display="block"> be left aligned with one space indent for 
 * compatibility with style conventions
 */
.mwe-math-fallback-image-display,
.mwe-math-mathml-display {
	margin-left: 1.6em !important;
	margin-top: 0.6em;
	margin-bottom: 0.6em;
}

Reducing the amount of space with margin-top: 0.4em; should give similar spacing. We can do this locally, anyone with the appropriate admin bit can do it. It would be better if people add this to their Special:MyPage/common.css so we can properly test in first before making it live.

It highly unlikely the implementation has changed, as it takes months to get the smallest change through code review. This bit of the CSS was added by me in 2015[1] and has not been changed since. --Salix alba (talk): 13:15, 4 February 2021 (UTC)

As a guess, the CSS is targeting the child elements of the actual sibling element, which is <div class="mwe-math-element">. This margin is probably not being collapsed, hence, irregular spacing relative to what would be available with <p>. (Regardless, I do not really understand why we're targeting the two classes rather than the parent.) --Izno (talk) 00:56, 5 February 2021 (UTC)

Wikipedia:Sandbox organiser

Sandbox Organiser A place to help you organise your work

Hi all

I've been working on a tool for the past few months that you may find useful. Wikipedia:Sandbox organiser is a set of tools to help you better organise your draft articles and other pages in your userspace. It also includes areas to keep your to do lists, bookmarks, list of tools. You can customise your sandbox organiser to add new features and sections. Once created you can access it simply by clicking the sandbox link at the top of the page. You can create and then customise your own sandbox organiser just by clicking the button on the page. All ideas for improvements and other versions would be really appreciated.

Huge thanks to PrimeHunter and NavinoEvans for their work on the technical parts, without them it wouldn't have happened.

Hope its helpful

John Cummings (talk) 11:31, 6 February 2021 (UTC)

Requested move 20 January 2021

The following is a closed discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review after discussing it on the closer's talk page. No further edits should be made to this discussion.

The result of the move request was: Moved. Generalized version moved to Generalized Stokes' theorem to be consistent. (non-admin closure) Vpab15 (talk) 22:54, 12 February 2021 (UTC)

---

• Kelvin–Stokes theorem → Stokes' theorem
• Stokes' theorem → Generalized Stokes theorem

– WP:COMMONNAME says that names used most frequently in reliable sources should be used on Wikipedia when a topic has multiple names or a name can be used for multiple topics. When I Google "Stokes' theorem" and search through sources like e-textbooks, university websites, and mathematical databases (which are presumably reliable for mathematical topics), they overwhelmingly refer to the "specialized" $\mathbb {R} ^{3}$ case. And when I search "Generalized Stokes theorem," there are plenty of hits for that case. On the other hand, when I search "Kelvin-Stokes theorem," there ARE reliable sources that use that name, but it's not the most commonly known or the most likely to be searched by someone wanting to know more about this case. While few people know enough mathematics to describe the "specialized" Stokes' theorem, even fewer would be familiar with the more general case. I know that when I went to Stokes' theorem on Wikipedia, I was expecting the vector-calculus case. In short, I think this move would make the articles more useful to the average reader. ChromaNebula (talk) 18:56, 20 January 2021 (UTC)

• Support: For both versions of the theorem, the most common name is Stokes' theorem, but yes, more of the people who search for Stokes' theorem are going to be looking for the version in $\mathbb {R} ^{3}$. "Kelvin-Stokes theorem" should be a redirect to the new Stokes' theorem page. The new "Generalized Stokes theorem" page should say in the lead that the more common name for the generalized Stokes theorem is simply "Stokes' theorem". Ebony Jackson (talk) 22:18, 20 January 2021 (UTC)
• Support: As both the nominator and Ebony Jackson noted, Stokes' theorem is the WP:COMMONNAME for both articles but the $\mathbb {R} ^{3}$ is far more common for a non-specialized audience. — MarkH₂₁^talk 22:23, 20 January 2021 (UTC)
• Comment: An alternative is to move Stokes' theorem → Generalized Stokes theorem, leave Kelvin–Stokes theorem where it is and create a dab called Stokes' theorem. That works best if neither article is a primary topic for "Stokes' theorem"; I'm not sure whether that is the case. (To me it means $\mathbb {R} ^{3}$, but I'm not a practicing mathematician.) Certes (talk) 00:02, 21 January 2021 (UTC)
  • One could do that, but given that they are two versions of the same theorem, one more general than the other, a DAB does not make so much sense logically, I'd say. Ebony Jackson (talk) 03:12, 21 January 2021 (UTC)
    • The alternative proposal below looks like a better way to achieve what I was attempting. Certes (talk) 13:03, 2 February 2021 (UTC)
• Comment: This discussion seems to be in the wrong place. RM discussions are supposed to be placed on the article Talk page of an affected article, not on the Talk page of a WikiProject, according to the instructions at WP:RM. — BarrelProof (talk) 02:01, 21 January 2021 (UTC)
  • I see your point. I actually asked at the help desk where to take this move discussion, and the staffer there told me to take it here because this is a highly technical topic. Mathematics pages also see so little traffic that a move request there might not generate adequate discussion. ChromaNebula (talk) 02:53, 21 January 2021 (UTC)
• Support but since "generalized Stokes' theorem" does not seem to be a standard name, I suggest we instead use the title "Stokes' theorem (general version)". -- Taku (talk) 02:14, 21 January 2021 (UTC)
• Comment: I'm unsure how typical this is, or how conforming, but if I were looking for Stokes' Theorem on Wikipedia as a user, then I might expect them both to be listed as Stokes' Theorem with disambiguation in brackets. E.g. I'd know straightaway that Stokes' Theorem (differential forms) was the general one. I'm less sure about the specialised version: maybe Stokes' theorem (classical); or Stokes' Theorem (line integral). NeilOnWiki (talk) 13:38, 21 January 2021 (UTC)
• Support the two moves as proposed (well, with the extra ' in the second version) -- the vector calculus version is clearly the primary topic here, and its common name is Stokes' theorem. I prefer natural disambiguation (generalized Stokes' theorem) to parenthetical disambiguation; of the parenthetical options, the best mentioned so far is Stokes' Theorem (differential forms). --JBL (talk) 14:16, 21 January 2021 (UTC)
• Support in agreement with JBL's comment. Did Mr Stokes work on this generalized form or was his theorem only about $\mathbb {R} ^{3}$. Very few people will ever have to deal with the generalized forms. Also, I can't seem to find any sources that call the theorem Kelvin-Stokes' theorem, that's definitely not its most common name. Ponor (talk) 15:54, 21 January 2021 (UTC)
  • According to this history, the basic theorem first appeared in a letter from Kelvin to Stokes, and Stokes put it on an exam for students, and the first published proof was by Hankel. So Stokes was responsible neither for the statement nor the proof. The generalized Stokes' theorem was not stated or proved by Stokes either; it is due to Cartan much later. By the way, the history I cited does use the term generalized Stokes' theorem, and I think some others do too, so it is not unreasonable to use that as a name for a Wikipedia article, even if the name used to describe the generalized version is more often just Stokes' theorem. Ebony Jackson (talk) 17:08, 21 January 2021 (UTC)

    An interesting read, thanks; this paper should be cited. Now, even Katz doesn't seem to suggest the theorem should be called Kelvin-Stokes' theorem, so we're left with the two references in Japanese - for those who can read - which, I'm afraid, isn't enough to claim most common use in English (WP:NCUE). Some credit should be given to Hankel, Kelvin & Tait in the article, per Katz's paper, but it's not on us, I think we all agree, to push this or that alternative name. Ponor (talk) 15:25, 25 January 2021 (UTC)

Alternative proposal

I'd like to see Stokes' theorem become a new broad concept article briefly covering both the original theorem and its generalisation.

To do this we would disambiguate the current article (but I'm not convinced that the proposed name Generalized Stokes theorem is particularly recognisable) and start a new BCA. The existing articles are both OK in what they cover.

I think this new article could be a very valuable one, particularly if it is kept short and approachable to the uninitiated. Andrewa (talk) 09:30, 2 February 2021 (UTC)

• After looking up broad-concept articles, I appreciate this proposal. However, I'm a physicist and not a mathematician, so I don't understand the general case enough to tell whether a BCA would be appropriate. I will leave that decision to the mathematicians of Wikipedia. ChromaNebula (talk) 23:50, 6 February 2021 (UTC)

---

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

About Oka's lemma

I think it's okay to merged it into Kiyoshi Oka. Oka's coherence theorem may also be included.--SilverMatsu (talk) 05:00, 12 February 2021 (UTC)

I wouldn't merge them. In both cases, I trust R.e.b.'s judgement about which topics should have separate articles, even if those articles were left in a very stubby state. —David Eppstein (talk) 05:15, 12 February 2021 (UTC)

I would agree that Oka's coherence theorem is important enough as a foundation result in its field (complex geometry and algebraic geometry) to warrant its own page, even if it is currently a stub. Kiyoshi Oka is a reasonably significant figure also, as one of the big early Japanese geometers, so should also obviously warrant their own page, so I would say don't merge those two. I can't speak with any confidence about Oka's lemma.Tazerenix (talk) 05:34, 12 February 2021 (UTC)

Thank you for your reply. I agree that Oka's coherence theorem is a separate page. However, it seems that Oka's lemma may be written on the pseudoconvex domain or the Levi's problem page. Currently, Levi problem is redirected to the Stein manifold, which seems more like Grauert's proof than Oka's proof. thanks!--SilverMatsu (talk) 06:05, 12 February 2021 (UTC)

I found three more sources in MathSciNet with "Oka's lemma" in the title (all about this specific lemma; there's another paper on a different Oka lemma). I think it clearly passes WP:GNG as an independently notable topic. —David Eppstein (talk) 06:34, 12 February 2021 (UTC)

Thank you for your reply. As for Oka's coherence theorem, it would be nice if I could prove it, but I think I'll probably have to wait 70 years from 1978. The content of the current Oka's lemma is a bit questionable, given that Levi pseudoconvex and Levi's problems are redirects. The current content semms like a pseudoconvex domain. In some cases, the content of Oka's lemma is defined as pseudoconvex. but, called Oka Pseudoconvex has a different meaning ...--SilverMatsu (talk) 07:30, 12 February 2021 (UTC)

Apparently, there are two more theorems called Oka's coherence theorem. To mention this, we need the following Oka's and Cartan paper. As for the ideal sheaf, Cartan also submits proofs independently, so it seems that this theorem cannot be merged on Kiyoshi Oka page. Special thanks to David Eppstein and Tazerenix for their advice. I would like to hear your opinion on adding these two coherence theorems to the page. thanks!--SilverMatsu (talk) 12:03, 13 February 2021 (UTC)

Combinatorial hierarchy

This looks like bad numerology, and it's entirely relying on primary sources because everyone apart from these few authors realizes it's not useful. Is there a good reason to keep this article? --mfb (talk) 22:23, 11 February 2021 (UTC)

Looks like 100% crankery to me. If it's notable enough for people to have written about the fact that it's crankery, then obviously such sources should be included; if not, AfD seems like a good option to me. --JBL (talk) 22:44, 11 February 2021 (UTC)

I'm not finding anything except a passing mention in an essay by I. J. Good about how, yes, you can screw around with numbers and get other numbers that look meaningful. I don't think that warrants an article. The biographies linked from combinatorial hierarchy also need attention. XOR'easter (talk) 14:00, 12 February 2021 (UTC)

All the work of H. Pierre Noyes uses "personal interview" as reference, great. That's arguably worse than Noyes writing his own article, we get all the issues of a person describing themselves plus the issue of having no reference that could be checked. All the work of Ted Bastin is completely unreferenced. --mfb (talk) 15:51, 12 February 2021 (UTC)

I'm really doubtful that Ted Bastin qualifies as wiki-notable. Nothing I'm turning up would count for passing WP:PROF or WP:AUTHOR; the best source is the Times obit that would only get partway to WP:GNG and that seems to have swallowed some fan remarks uncritically. For example, it mentions the original home of Rupert Sheldrake's work on morphic resonance without saying that Sheldrake's "work" is rank pseudoscience. And it says, The link between quantum physics and information theory, in a broad sense, has grown stronger in recent years, as computer scientists investigate the possibility of quantum physics providing a new basis for computer hardware and, simultaneously, quantum physicists investigate the information basis of their subject. But there is little recognition in recent research of the origin of the latter idea in the pioneering work of Bastin and others. The "and others" does a lot of work there: Bastin himself isn't even a marginal figure in the history of quantum foundations and quantum information. XOR'easter (talk) 17:41, 12 February 2021 (UTC)

H. Pierre Noyes, Ted Bastin, Clive W. Kilmister and H. Dean Brown were all started and largely written by the same user. Brown looks okay, Kilmister is probably relevant but the article doesn't do a good job making that clear. --mfb (talk) 21:55, 15 February 2021 (UTC)

Wikipedia:Articles for deletion/Combinatorial hierarchy --mfb (talk) 21:36, 15 February 2021 (UTC)

Mary Ann Mansigh

deletion discussion

---

Female programmer, co-creator of moldyn method. Yo, we all need to come out for this one, especially if you're in the computational community in phy sci, bigly. Already posted on super- science wp's forum, and several sub-forums as well. It's not certain enough, and too close for my liking. Ema--or (talk) 02:26, 12 February 2021 (UTC)

Sorries all round for my non-NPOV canvas! Ema--or (talk) 21:14, 15 February 2021 (UTC)

Hi, just an issue to discuss. Just wanted to name an issue, which I asked for consultation on, but was not able to get any thing on before the end of discussion. There is the issue of my inconsistencies on Mansigh btw main space and other-space, particularly afd- and Wp project-space, although it is particularly a matter for subjective interpretation. I’d like to end by again apologising for any trouble and thanking anyone who offered any opinion or contribution to the chat, as well as for the space and audience in a place such as this. Bye, ‘til next time. Ema--or (talk) 18:28, 18 February 2021 (UTC)

about Draft:Division by infinity

I don't know where to write a consultation about the article being drafted, so I chose it here. I was wondering if I could create a talk page for the draft space. I think that the harmonic series is related to Draft:Division by infinity. This series diverges to infinity, but in the Basel problem it converges to ${\frac {\pi ^{2}}{6}}$. It seems that this series can be regarded as adding the number divided by infinity from the middle of the sequence, but the calculation result is different. I may have overlooked the boundary between infinity and finite. thanks!--SilverMatsu (talk) 12:52, 7 February 2021 (UTC)

The harmonic series and the Basel series are completely different series! —JBL (talk) 13:34, 7 February 2021 (UTC)

Thank you for your reply. Oops, it was a bit (quite?) strange, as it semms like a Hazel problem in harmonic series in my context. I wrote it with the intention of comparing numbers divided by infinity, but for example, the sum of the reciprocals of prime numbers does not converge, but this may be a problem of the spacing between terms rather than the size of each term.--SilverMatsu (talk) 04:47, 8 February 2021 (UTC)

Can you help convince me that an article entitled "Division by infinity" is needed? Would you also make separate articles entitled "Infinity plus zero" and "Infinity divided by infinity" and "Infinity times zero", etc.? It is quite different from the situation with Division by zero, which is about attempting to apply an arithmetic operation to actual numbers, something that students initially expect to be able to do.

As for the content of the article, about half of the sentences right now seem like pseudo-math, without a precise mathematical meaning. Is there a published article or book that has an exposition similar to the one you are presenting? Ebony Jackson (talk) 08:37, 8 February 2021 (UTC)

Thank you for your reply. Sory, I don't have any helpful literature. In this article, I seems that the meaning of infinity in elementary arithmetic was a monotonically increasing sequence of real numbers. And this article seemed to try to explain what the numbers calculated by Division by infinity are. I tried to compare the example of the calculation result, but I didn't have a concrete idea of ​​how to edit it to improve the article. I tried to help with this article, but it's not working. thanks!--SilverMatsu (talk) 10:57, 8 February 2021 (UTC)

Ebony Jackson makes important points. If you choose to continue to develop this draft, my advice is to (A) locate Wikipedia:Reliable sources and then (B) summarize those sources. I mean, don't wait until later to find sources. Because if you can't find sources, or if your text doesn't reflect those sources, then your work might come across as Wikipedia:Original research, which will not be accepted into the encyclopedia. Best wishes. Mgnbar (talk) 13:14, 8 February 2021 (UTC)

That draft started as a student's class project; I happened across it and took a few stabs at making it into an article but never got far enough that I considered it mainspace-ready. If anyone would like to try, the Beyond Infinity book listed at the end might be a decent place to start. XOR'easter (talk) 14:59, 8 February 2021 (UTC)

XOR'easter thank you for the advice. I will search for references. In the references I have now (I don't have Beyond Infinity) , I can provide related examples, but I am not writing from the perspective of dividing by infinity, so I will continue to search for references. thanks!--SilverMatsu (talk) 13:15, 9 February 2021 (UTC)

I am still skeptical that an article on "Division by infinity" should exist at all. I would suggest that you spend your valuable time elsewhere! Ebony Jackson (talk) 18:47, 9 February 2021 (UTC)

I am also skeptical. But if there are many reliable sources that talk about this concept, saying non-trivial things that aren't covered elsewhere in Wikipedia, then maybe this article should exist. In other words, I think that that part of the discussion also hinges on reliable sources. Mgnbar (talk) 19:17, 9 February 2021 (UTC)

I would be surprised if there were lots of high-quality reliable sources calling out "division by infinity" as a separate topic. You can divide by infinity in some contexts, certainly; the most common is probably the Riemann sphere, which doesn't actually seem to be mentioned in the draft as it stands. --Trovatore (talk) 19:36, 9 February 2021 (UTC)

Mgnbar Thank you for the advice. I would like to lower the priority of this article in my to-do list. If this article can exist as a separate article, I've come to think that references will naturally come together while improving other articles. Thank you for taking your time. --SilverMatsu (talk) 07:03, 10 February 2021 (UTC)

Why not post the article? Looks ready to me.... Ema--or (talk) 02:45, 12 February 2021 (UTC) Still waiting, huh? Ema--or (talk) 22:10, 18 February 2021 (UTC)

Are you interested in writing ${\frac {a}{\infty }}=0$ (a is a finite real constant number) as follows? $x_{n}={\frac {a}{n}},\ \{{}^{\forall }\varepsilon >0,\;{}^{\exists }N\in \mathbb {N} \;\mathrm {s.t.} \;{}^{\forall }n\in \mathbb {N} \;(n>N\Rightarrow |x_{n}-0|<\varepsilon )\}$ It may overlap with the content of (ε, δ)-definition of limit article ...--SilverMatsu (talk) 03:18, 14 February 2021 (UTC)

Zero to the zero power

I would like advice about the lead of the article Zero to the zero power. The question is which of the following should be used as a lead (perhaps the answer is some hybrid of the two).

Possibility 1:

Zero to the power of zero, denoted by 0⁰, is a mathematical expression with no agreed-upon value. The most common possibilities are 1 or leaving the expression undefined, with justifications existing for each, depending on context. In algebra and combinatorics, the generally agreed upon value is 0⁰ = 1, whereas in mathematical analysis, the expression is sometimes left undefined. Computer programming languages and software also have differing ways of handling this expression.

Possibility 2:

Zero to the power of zero, denoted by 0⁰, is a mathematical expression that arises most commonly as a value of the function x⁰ or as a limiting form.

• As a value, especially as a value of the constant function x⁰, one has 0⁰ = 1.
• As a limiting form, 0⁰ is indeterminate. This statement means that the limit of a function of the form f(x)^g(x) cannot be determined just from knowing that the limits of f(x) and g(x) are 0: different values are possible, or the limit may fail to exist, depending on what the specific functions f(x) and g(x) are. Because of this, some textbook authors prefer to leave the value 0⁰ undefined, but Knuth and others argue that this is a mistake.

Computer programming languages and software have differing ways of handling the expression 0⁰.

In Possibility 1, many of the same references would be used, just later in the article. (The situation is that one of these was changed to the other one, and then reverted. For the reasons supporting each lead, you can see the history of Zero to the zero power.) Ebony Jackson (talk) 01:51, 10 February 2021 (UTC)

• Possibility 1. It's not acceptable to say that 0⁰ has an agreed-upon value, because it doesn't. --Trovatore (talk) 01:57, 10 February 2021 (UTC)
• Possibility 2. (Full disclosure: I was the one who changed 1 to 2, and Trovatore was the one who reverted it.)

There is a consensus that 0⁰ is an indeterminate form. There is also a consensus that the value of the constant function x⁰ at 0 is 1. These seem to be the useful points from the mathematical literature that this article should focus on. I don't think it is correct to say only that is field-dependent, since for example, in analysis one needs 0⁰ = 1 for the power rule of calculus. I think it is important to distinguish the use of 0⁰ as a value and its use as a limiting form. Ebony Jackson (talk) 02:25, 10 February 2021 (UTC)

That's different, because the exponent in that case is a natural number. When the exponent is a real number, the situation is much less clear. --Trovatore (talk) 02:36, 10 February 2021 (UTC)

It would be helpful to know if there are notable authors who distinguish "0 the integer" from "0 the real number" when deciding whether to define 0⁰, someone at the level of Donald Knuth, who in his 1992 paper argues quite forcefully for disambiguating 0⁰ according to whether it is being used a value or a limiting form, and who says that 0⁰ has to be 1. I think Benson describes the mathematical literature accurately when he writes, "The consensus is to use the definition 0⁰ = 1, although there are textbooks that refrain from defining 0⁰", though he does not have the authority that someone like Knuth has. Ebony Jackson (talk) 02:47, 10 February 2021 (UTC)

There are any number of texts that define $x^{y}$ as $e^{y\log x}$, which is not defined at the point (0, 0). Mostly they don't make a point of noting that this is a different function from the repeated-multiplication function also called exponentiation and notated $x^{n}$, but nevertheless they do not give a definition to the first function at the point (0, 0).

Summary is that Knuth made a reform proposal that has gained some, but not full, acceptance, and Benson is wrong to claim a consensus. --Trovatore (talk) 02:52, 10 February 2021 (UTC)

It can hardly be called a reform proposal: It was Euler that stated that 0⁰ = 1, and he was considering both natural number and real exponents! I would still be happy to know of notable authors (say, notable enough to have a Wikipedia page) who argue as you do, that one defines 0⁰ = 1 when the exponent is viewed as a natural number and undefined when the exponent is viewed as a real number.

In any case, let me see if the following compromise incorporating your comments might be better:

Possibility 3:

Zero to the power of zero, denoted by 0⁰, is a mathematical expression that arises most commonly as a value of the function x⁰ or as a limiting form.

• As a value, especially as a value of the constant function x⁰, the consensus is to define 0⁰ = 1, but there are textbooks that refrain from defining 0⁰ in contexts where real number exponents are involved.
• As a limiting form, 0⁰ is indeterminate. This statement means that the limit of a function of the form f(x)^g(x) cannot be determined just from knowing that the limits of f(x) and g(x) are 0: different values are possible, or the limit may fail to exist, depending on what the specific functions f(x) and g(x) are. This is the reason that some textbook authors prefer to leave the value 0⁰ undefined, but Knuth and others argue that this is a mistake.

Computer programming languages and software have differing ways of handling the expression 0⁰.

No, it's not acceptable to say in Wikipedia's voice that the expression has a consensus value. We can attribute that assertion to Benson if you like, but further down. --Trovatore (talk) 03:32, 10 February 2021 (UTC)

If you don't like to distinguish between 0 the natural number and 0 the real number, think of it instead as distinguishing between the function defined on R×N and the one defined on R_>0×R. --Trovatore (talk) 03:36, 10 February 2021 (UTC)

I think that you-all are ignoring the larger problem — how is exponentiation defined. If we define it with (repeated multiplication) a complex base and natural number exponent, then 0⁰=1. If we define it with (exp and ln) a positive real base and a complex exponent, then 0⁰ is undefined. JRSpriggs (talk) 03:41, 10 February 2021 (UTC)

I totally agree, except that I don't think I was ignoring that :-) . --Trovatore (talk) 03:43, 10 February 2021 (UTC)

Indeed, I think Trovatore's previous comment was essentially that. Trovatore's interpretation is worth including in the article, if there is a source for this by a notable author. Does someone know one?

As for whether there is a consensus that 0⁰, when considered as a value (as opposed to a limiting form), is 1: Maybe it is right that it is not a consensus; if that's the case, we should be able to back that up with modern notable references. So far we have Knuth (and I could also give you books by Lang and others that define x⁰ = 1 even for x = 0). I'd like to see the references that argue that the value 0⁰ (and not just the limiting form) should be left undefined. So far, there have been none provided in this discussion.

I hope that at least we can agree that there are no reputable authors assigning it a specific value other than 1, and that there is a consensus that the value of the function x⁰ at x = 0 is 1. Ebony Jackson (talk) 04:34, 10 February 2021 (UTC)

I don't think Benson's claim is enough to say that there is a consensus.

As for the "function x⁰", I think it depends what you mean. The monomial, yes. But powr is not defined at (0.0, 0.0), no matter whether you start by writing powr(x, 0.0) and then pass 0.0 for x. --Trovatore (talk) 04:48, 10 February 2021 (UTC)

Yes, Benson's claim is not enough; so I was mentioning Knuth and asking if anyone knew similarly notable references that argue that the value 0⁰ (and not just the limiting form) should be left undefined. Ebony Jackson (talk) 05:08, 10 February 2021 (UTC)

No, those others don't assert a consensus, whereas there are lots of sources that simply don't define the value. There is not enough to assert a consensus in Wikipedia's voice. --Trovatore (talk) 05:32, 10 February 2021 (UTC)

I believe you, that such sources exist, but it is not what I believe that matters. I think we would all be happier if someone could list at least one source written by an authority in the field that says not only that the limiting form is indeterminate, but that the value should be left undefined. Ebony Jackson (talk) 05:55, 10 February 2021 (UTC)

I prefer "possibility 1". I do not think the two back to back sentences about what the value is and where it is that value are sufficiently concise (i.e. they are repetitive), but this is a tangential concern. --Izno (talk) 04:41, 10 February 2021 (UTC)

• I also prefer possibility 1. I am not convinced that there is a consensus of algebraists or combinatorists or valuators, as asserted in the other choices, and we should not be picking winners ourselves (here, "teach the controversy" is actually appropriate). —David Eppstein (talk) 06:00, 10 February 2021 (UTC)
• Possibility 1 for now – the first three cited sources show authors who need it to be 1, but don't really establish that there is a consensus that the value is 1. Yes, in certain contexts such as Knuth's combinatorics stuff, it needs to be defined as 1 to be correct, or else lots of nasty hoops need to be jumped through to avoid it. So you need a way to say that: that is some contexts giving it the value 1 makes things correct and easy, while leaving it undefined or giving it any other value makes things wrong or too complicated, so in those contexts it is often taken to stand for 1. But this doesn't need to be in the lead. And thanks for that Knuth paper – a great read like most of his works. Dicklyon (talk) 06:06, 10 February 2021 (UTC)

@David Eppstein: Yes, we should not be picking winners. I too think that it is not right to say that entire fields of mathematics interpret 0⁰ uniformly one way or the other. It is not so much field-dependent as it is context-dependent. (I guess we would all agree that the binomial theorem and the power series for 1/(1-x) are all over math, not really limited to a particular area.)

@Dicklyon: I agree with much of what you wrote. I think it would not be too hard for the lead to broadly identify the contexts in which 0⁰ is defined to be 1, the contexts in which 0⁰ is left undefined (such as when it is a limiting form), and the contexts where there is controversy, whatever they end up being. The details could be left to later in the article, as you suggest. Given the comments that have been made so far, I am no longer happy with either possibility 1 or possibility 2 as written.

It would be nice to have authoritative references beyond Knuth 1992, so that we are not relying only on people's impressions. Thank you, Ebony Jackson (talk) 06:37, 10 February 2021 (UTC)

• possibility 1 seems fine to me.--Kmhkmh (talk) 17:57, 13 February 2021 (UTC)

References

Thank you all for your comments. These are the lessons I have learned from all of you:

• Possibility 2 does not accurately reflect the consensus (at least among the editors here; it would still be nice, however, to have authoritative references beyond Knuth).
• It goes too far in saying that the value of 0⁰ is 1.
• The statement should be limited to contexts in which only nonnegative exponents are being considered. As Trovatore points out, it is helpful to think about there being two different exponentiation functions, one defined on R×N and one defined on R_>0×R. They agree where both are defined, so they could be combined, but not all authors do so.
• Moreover, it would be better, instead of saying that the value of 0⁰ in nonnegative exponent contexts is 1, to say only that the choice to define 0⁰ as 1 is necessary for many standard identities.
• In contexts where real and/or complex exponents are considered, there are authors who say not only that the limiting form 0⁰ is indeterminate, but also that the value 0⁰ should be left undefined. (It would still be good to have an authoritative reference for this. I'd be curious to know, for instance, what the analysis books by Rudin, Spivak, Stein and Shakarchi, Tao, etc., have to say on this if anything, if someone has access to these.)

I will think about whether it is possible to draft a version of the lead that reflects the points you all made. I think it should be possible; maybe one of you would like to try. I don't have time at the moment, but maybe later if no one tries it, I can draft something and ask all of you for feedback again.

Best, Ebony Jackson (talk) 18:57, 12 February 2021 (UTC)

Wow, major props to author(s). What's holding the draft above? It'd make an excellent link to this article. At least, stub, at very least. Ema--or (talk) 22:14, 18 February 2021 (UTC)

AfD and marginal point-of-view pushing

I have nominated 2 × 2 real matrices for deletion. See Wikipedia:Articles for deletion/2 × 2 real matrices, and, please, contribute.

Looking at the incoming links to this article, it appeared that few of them may simply replaced by a link to square matrix, but most reveal a long term point-of-view pushing by fans of the old-fashioned terminology of hypercomplex numbers. This point-of-view pushing consists not only of adding links, but generally also of adding a gibberish that is full of mathematical errors and use of never defined terminology. See my recent edits and the remaining incoming links to 2 × 2 real matrices. So, help would be welcome for fixing the sources of these incoming links. This fix is sometimes difficult, as links to 2 × 2 real matrices are generally used as WP:SUBMARINE for pushing the point of view of hypercomplex numbers, and also as the gibberish use plenty of reference to sophisticated mathematical and physical theories (Lorentz group, general relativity, etc.) that seem irrelevant, although I do not know them enough for being able to decide wheter these references are WP:original synthesis. So, again, help is welcome. D.Lazard (talk) 18:24, 19 February 2021 (UTC)

proposed expansion to MATLAB page

I proposed a draft of an expanded history section for the MATLAB page (mathematics software) here in compliance with WP:COI. I pinged mathematician @Jakob.scholbach: here to see if he would be interested in reviewing the proposed content to ensure compliance with Wikipedia’s rules and principles. He suggested I post here, so here I am! If anyone is willing to take a look at the draft history section, any feedback and/or approval/implementation of some or all of the content would be appreciated. Lendieterle (talk) 18:57, 17 February 2021 (UTC)

Just noting that I looked over the suggested material and added it to the page after making one minor change. Brirush (talk) 03:38, 20 February 2021 (UTC)

S. L. Woronowicz

Shouldn't the article be renamed to Stanisław Lech Woronowicz with full name of the person? --CiaPan (talk) 17:19, 16 February 2021 (UTC)

See WP:COMMONNAME and MOS:BIO — usually we title articles by the most common name for the person (for academics, that might either be the name they publish under, or the form of the name they would use in real life) even though we spell out the full name at the start of the article. I don't have evidence for what version of the name he prefers in real life (for instance, his first name could reasonably be abbreviated either Stan or Stas) but many of his publications (especially the earlier ones) seem to use the initials, so that's a reasonable choice for article title. He has also published as Stanisław L. and Stanisław Lech, though. —David Eppstein (talk) 17:48, 16 February 2021 (UTC)

Not an answer to this question, but there are not a lot of people with this name running around, so it would be natural for three of { S. L., Stanisław, Stanisław L., Stanisław Lech } to be redirects pointing to the fourth. --JBL (talk) 18:00, 16 February 2021 (UTC)

The Polish Wikipedia uses pl:Stanisław Woronowicz, his website just lists his full name, his email address (on the website) uses stanislaw, his arXiv account uses Stanisław. Simply taking firstname lastname might be the best approach here. --mfb (talk) 20:40, 16 February 2021 (UTC)

Keep title. I agree with David Eppstein: Since it seems clear that he prefers to publish under the name S. L. Woronowicz, I think it best to leave that as the title of the article. Then, as JBL suggests, have the variants redirect to that article. Ebony Jackson (talk) 17:13, 17 February 2021 (UTC)

Thank you all for your opinions. I understand the result is to keep the current name. I've put a note about this discussion at the article's talk page. --CiaPan (talk) 11:52, 21 February 2021 (UTC)

Mar 2021

about Oka–Weil theorem

Like Runge's approximation theorem, I'm thinking of creating Oka–Weil approximation theorem as a redirect to Oka–Weil theorem. If it's often called Oka–Weil approximation theorem, move the page. thanks! --SilverMatsu (talk) 02:56, 27 February 2021 (UTC)

@SilverMatsu: Some sources do use the name "Oka–Weil approximation theorem" (e.g. this one), but I don't think it is more common than just "Oka–Weil theorem". A redirect is still warranted though. — MarkH₂₁^talk 04:12, 2 March 2021 (UTC)

Thank you for providing a helpful reference for the title of the article and creation of the redirect.--SilverMatsu (talk) 04:31, 2 March 2021 (UTC)

Variational distance as a String metric?

Please see my question at Talk:String metric#Variational distance. --CiaPan (talk) 11:09, 4 March 2021 (UTC)

Uniform Boundedness Conjecture

We now have an article Uniform Boundedness Conjecture, and a redirect uniform boundedness conjecture pointing to torsion conjecture. They're both on finiteness of sets of points in arithmetic geometry but one is on torsion points and the other is on rational points. Can someone who understands the relations among these principles help clean up this duplication of titles, please? —David Eppstein (talk) 21:16, 22 February 2021 (UTC)

There are now several conjectures in arithmetic geometry that are called the "uniform boundedness conjecture", which all have essentially the same origin. To my understanding, the uniform boundedness conjecture about torsion points at torsion conjecture by Ogg (1973) was the starting point. After the proof of the Mordell conjecture by Faltings in 1983, the adaptation to rational points (which include the torsion points over the rationals) at Uniform Boundedness Conjecture was the next generalization. Now, there is also the uniform boundedness conjecture in arithmetic dynamics posed by Morton and Silverman in 1994.

They are all known by the name "uniform boundedness conjecture", but they are often specified (e.g. Uniform boundedness for rational points). I would suggest:

• Uniform boundedness conjecture for torsion points as a redirect to Torsion conjecture
• Uniform boundedness conjecture for rational points as the title for what is currently Uniform Boundedness Conjecture
• Uniform boundedness conjecture for preperiodic points as a redirect to Arithmetic dynamics#Number theoretic properties of preperiodic points
• Uniform boundedness conjecture as a disambiguation for the three above, as well as any other similarly named notions

Plus, it might be useful to make redirects at similar titles (e.g. Uniform boundedness conjecture (torsion points), Uniform boundedness conjecture (rational points), Uniform boundedness conjecture (arithmetic dynamics)). I also would not be surprised if there are other uniform boundedness conjectures (e.g. following the Uniform boundedness principle). — MarkH₂₁^talk 21:59, 22 February 2021 (UTC)

That sounds reasonable. By the way, Ogg's conjecture on torsion of elliptic curves over Q was essentially formulated earlier by Beppo Levi at the 1908 ICM, and then again by Trygve Nagell in 1952. See the article "Beppo Levi and the arithmetic of elliptic curves" by Schappacher and Schoof. Ebony Jackson (talk) 05:50, 23 February 2021 (UTC)

Just carried out the proposal and added the background on Levi and Nagell to Torsion conjecture as well! — MarkH₂₁^talk 09:11, 25 February 2021 (UTC)

There are four links to the disambiguation page left. Can someone take a look at these? Thanks! Lennart97 (talk) 20:42, 5 March 2021 (UTC)

@Lennart97: Done. Thanks for the notice! — MarkH₂₁^talk 22:02, 5 March 2021 (UTC)

Math formatting in Particular values of the Riemann zeta function

A discussion at Talk:Particular values of the Riemann zeta function on how to format the display-equations in that article could use wider participation by mathematics-savvy editors. —David Eppstein (talk) 19:35, 6 March 2021 (UTC)

Abominable typesetting in illustrations

Examples of scatter diagrams with different values of correlation coefficient (ρ)

Probably a solid majority of images in Wikipedia article that contain mathematical notation have a quality of typesetting worthy only of cavemen. Will that ever be done something about?

Note:

${\begin{aligned}&\rho ={\text{-}}{\mathit {1}}\quad {\text{instead of }}\rho =-1\\&{\text{i.e. “-” instead of “}}{-}{\text{” and “}}{\mathit {1}}{\text{” instead of “}}1{\text{”}}\\[8pt]&{\text{-}}1{<\rho <}0\quad {\text{instead of }}{-1}<\rho <0\\&{\text{Here the issue is not just the hyphen instead of}}\\&{\text{a minus sign, but the lack of proper spacing.}}\end{aligned}}$

Michael Hardy (talk) 18:15, 9 March 2021 (UTC)

I fear that it would take a tremendous drive to fix all the poor quality typesetting in the images, as someone would need to remake all the diagrams. I try to use mathcha to make mine, which is fairly easy and when you put in text it formats it in LaTeX format. The alternative is to get people to create their diagrams in an actual LaTeX document, but it is a bit technically difficult to export such things in good formats like SVG or PNG at good resolution without some knowhow. Perhaps we could add such a website like mathcha to the style guide? It seems to me that a more critical problem than the bad typesetting in the current diagrams is that many articles could do with a lot of new diagrams to explain concepts, and if we were going to have a drive I'd rather it be for us to go through and put some good new diagrams in as many articles as we can; then the population of maths diagrams would asymptotically approach all being well typeset. My 2c.Tazerenix (talk) 00:07, 10 March 2021 (UTC)

WP:FA devoid of STEM material

STEM articles are extremely underrepresented in WP:FA, and of the few that do exist, many are about products or services, biographical, or otherwise of a non-technical nature. I propose a review of top/high-importance articles in STEM to determine exactly what must be done in order for them to meet the featured article criteria, make appropriate edits, and award them featured article status as soon as possible, without delay. Particularly, material that is fundamental and important to scientific literacy in general or across multiple disciplines. I believe there must be a coordinated effort. Many scientific articles seem to become overly long and disjointed, with so many editors working independently. As a starting point, I think these three articles are all vital to basic scientific literacy and deserve very serious attention: Mean, Function (mathematics), Set (mathematics). My time is limited and I cannot improve them alone, but I would like to be part of such an effort. If at least a couple editors are interested, I'd like to set up an agenda, perhaps with a regular meeting. Once an article is agreed upon, we can read it, report back with comments, discuss how it can be raised to featured article status, and decide on specific edits. AP295 (talk) 20:11, 9 February 2021 (UTC)

I'd like to first establish some consensus about what a given article (starting with Mean) needs to meet WP:FA? standards. Lacking an agenda that interested editors can agree upon, it seems like many efforts to improve technical articles degenerate into content disputes and edit wars. To avoid that outcome, and to make edits productive toward WP:FA?, I humbly ask interested editors to share their suggestions and comments here, or hold their peace when I do edit the article.

• In what ways does the article Mean fall short of meeting WP:FA? criteria?

When I have some time I'll read the article in full and return with my own suggestions/comments. In the meantime, please feel free to share your own. Please make clear, actionable suggestions. AP295 (talk) 13:59, 10 February 2021 (UTC)

I'd also like to link this discussion in that article's talk page. Is there a nicer way to do this in wikimarkup than just pasting the URL? AP295 (talk) 14:06, 10 February 2021 (UTC)

There is a long-term established consensus about what are WP:FA standards (see WP:FA and MOS:MATH). For mathematical articles, there is a further consensus that needs rarely to be explicited: a mathematical article requires to be mathematically correct. So, opening a general discussion on that (I do not talk of a discussion on a specific point) is a waste of time for every participant to this discussion. So, I strongly suggest to close it immediately. D.Lazard (talk) 15:35, 10 February 2021 (UTC)

Please make clear, actionable suggestions about developing/improving the article Mean. AP295 (talk) 15:38, 10 February 2021 (UTC)

The article Mean illustrates the difficulty mathematics articles have in getting to WP:GA or WP:FA standard. If we read the lead of the article we come across this formula ${\displaystyle \mu =\sum xp(x)....}$. That will instantly trigger a too-technical complaint from a reviewer. The whole intro is packed full of technical terms. For an example take this quote from Wikipedia:Featured article review/Euclidean algorithm/archive1

So, considering that the article has been quite substantially rewritten since it passed FAC, and the version that passed FAC was decipherable at least in English, I suggest that the first step towards preserving Featured Status here is a revert to that version. Making math digestible is not rocket science: textbooks and other websites do it all the time-- we can, too.

This comes from User:SandyGeorgia who is quite involved in the FAC process.

Unfortunately she is wrong. Making maths decipherable and digestible is very hard, some brave souls have managed it and any FA takes a lot of time to produce. The textbooks and website she mentions manage to make small parts of a whole topic digestible, but fail the other FAC of comprehensive: it neglects no major facts or details and places the subject in context;. And there are parts of the mean article with some quite complex major facts. This tension between digestible and technically correct and comprehensive make any STEM topics a tricky one for FA. Others in the project have had much more success with getting articles through GA and it is a more achievable task. --Salix alba (talk): 17:47, 10 February 2021 (UTC)

The mean is an uncomplicated concept and will lend itself to an uncomplicated wiki article with a bit of work. AP295 (talk) 19:27, 10 February 2021 (UTC)

Regarding sigma notation, I think we can avoid it in the introduction in favor of using something like (a1 + a2 + ... + an)/n or p1 a1 + ... + pn an, but possibly make use of it when needed in the body of the article. The intro should be accessible to the casual reader and the body can include more technical content (and the notation that comes with it) for completeness. AP295 (talk) 19:57, 10 February 2021 (UTC)

I don't think the concept of average is simple. Claiming that Grandi's series is ${\frac {1}{2}}$ is also average in a sense. 1 − 2 + 3 − 4 + ⋯ cannot be averaged by the Cesàro mean. These are, in a sense, averages, claiming that the averages cannot always be defined.--SilverMatsu (talk) 00:13, 11 February 2021 (UTC)

That's kind of neat, but probably outside the scope of the article. I think Arithmetic mean, Expected value, Average could be merged into a single article. Most people are probably looking for expected value, and it should be given due weight. Currently, Mean is really just a laundry list of various things that people call a "mean", so I'm not exactly sure what to do with it or whether our efforts might be better spent cleaning up and merging the former three. The replies so far have been tepid at best and I'll be pretty busy with other work for a while but I'll leave this RfC open and try to make time at some point. AP295 (talk) 01:50, 11 February 2021 (UTC)

• Misplaced RFC. The place to discuss whether an article (that you think meets FA standards) actually does is in an FA nomination. The place to discuss how to improve that article (whether up to FA standards or otherwise) is on the talk page of the article. Whether the FA standards actually work or can be made to work for mathematics content (as in Salix alba's comment above) is a broader topic that is more appropriate here. As SA says, it has been possible to get even quite technical articles through the Good Article review process. It still takes significant efforts to make the mathematics understandable but there is a greater likelihood of that effort being rewarded. As Mean is not currently GA, that step seems like it should go first. To my mind it is not yet close to GA (it's rated B but I think it's more like C, mostly because it is too haphazard and has a lead that is entirely about one thing but a body about something else) but other GA reviewers might disagree. —David Eppstein (talk) 18:27, 10 February 2021 (UTC)

I do not think it meets FA standards. When it gets to that point, I'll take it up with the folks at FA nomination. I was going to make a topic on Mean's talk page too once we have a general idea of what must be done, but as the problem concerns more than just one article, I believe this is a good staging area. AP295 (talk) 18:58, 10 February 2021 (UTC)

Part of the problem I'm seeing is that Mean, Arithmetic mean, Expected value, and Average are four separate articles, with a lot of redundant content between them. There must be a better way to organize this information, preferably into a single article, or a couple of articles at most AP295 (talk) 01:59, 11 February 2021 (UTC)

Let's not forget centroid and center of mass. —David Eppstein (talk) 02:06, 11 February 2021 (UTC)

I can't tell if you're being a smartass or not. At the very least, Arithmetic mean, Expected value, and Average could probably be integrated into a single article. There's a lot of redundancy between the three and having them in a single article would make their relation clearer. Less is more, sometimes. AP295 (talk) 02:12, 11 February 2021 (UTC)

Actually, the articles Average and Mean seem to be trying to do the same thing, so they could be put together. Merging Expected value and Arithmetic mean into a single article would probably work fine as well. All four are a mess and need a lot of work, even if they are to remain four separate articles. AP295 (talk) 02:42, 11 February 2021 (UTC)

I would oppose a merge of Average and Mean. The common name "average" is broader than "mean", not just technically (since "average" can refer to other measures of centrality) but also in not-explicitly-mathematical applications, where averages are often a rough description of centrality in a concept that isn't precisely quantified. The page Average needs a lot of work, but much of that work should build out meanings that aren't redundant with the content at Mean. - Astrophobe (talk) 02:53, 11 February 2021 (UTC)

There's also central tendency, which shares plenty of content with the others. The articles centroid and center of mass are different from what we're talking about here, so I'm not considering them at the moment. "The page Average needs a lot of work, but much of that work should build out meanings that aren't redundant with the content at Mean." I think that would be difficult. Do you think there's any way to condense Average, Mean, Expected value, Arithmetic mean and central tendency into fewer than five articles? And if not, how should we define the scope of each article? AP295 (talk) 03:38, 11 February 2021 (UTC)

In what sense are centroid and center of mass different? They are the same as the expected value of a uniform distribution over the shape they are defined over, for instance. And the centroid is certainly in wide use as a central tendency. But we do need to distinguish the general idea of a mean, center, or central tendency from the specific additive versions described in average and expected value. —David Eppstein (talk) 04:56, 11 February 2021 (UTC)

That's fine, but then how should the article Mean be written differently from Average? Part of the challenge seems to be in agreeing upon the scope of any given article. AP295 (talk) 05:32, 11 February 2021 (UTC)

For example, is the table "Expected values of common distributions" in Expected value necessary? And I do like that it includes a few proofs, but as far as I know there isn't supposed to be any collapsed-by-default content in articles. AP295 (talk) 05:45, 11 February 2021 (UTC)

Centroid assumes a uniform mass distribution; center of mass does not necessarily. Dicklyon (talk) 19:54, 11 February 2021 (UTC)

@Dicklyon: DE meant "In what sense are centroid and center of mass different [from what we are talking about here]?", not "... different [from each other]?" (It is a response to the comment by AP295.) --JBL (talk) 19:56, 11 February 2021 (UTC)

That's what I get for reading from the bottom instead of the whole conversation. Sorry. Dicklyon (talk) 01:02, 12 February 2021 (UTC)

Dick, YOU'RE FIRED! My point was that those articles are pretty distinct from Average, Mean, Expected value and Arithmetic mean which have a lot of duplicate and/or unnecessary content and do not adequately distinguish themselves from the others. It's fine to keep them separate, I have no problem with that, but then we should try to make them clearer and more concise so that the reader understands the distinction, and the relation, between those concepts. AP295 (talk) 15:22, 12 February 2021 (UTC)

Have a look at the Average article. I think it might stand a better chance of getting promoted than mean. Its aimed more at a general reader, has less technical details. FA encourages summary style and the Average article already uses that quite a lot. --Salix alba (talk): 01:00, 12 February 2021 (UTC)

I don't believe "summary style" necessarily means "non-technical". WP:FA? is a very general and concise standard of quality, and to me it sounds like a cop-out when people claim that it disfavors technical or scientific articles. AP295 (talk) 19:59, 12 February 2021 (UTC)

And in fact, Principal component analysis, the first article I ever edited, is a good example of something that could be written much more concisely. I attempted to do just that but didn't get much past the lead, though at least I was able to improve it somewhat. It's not so much that these articles can't be written in summary style, but at least half the time I try to remove anything or reorganize/reword content in an article, other editors come out of the woodwork and go apeshit. That is part of the reason we're having this RfC, so that we can all get on the same page instead of getting into a week-long brawl that ends up on WP:ANI. I don't have the time for that bullshit. AP295 (talk) 17:07, 13 February 2021 (UTC)

• In what ways does Function (mathematics) fall short of meeting WP:FA? criteria?

• In what ways does Set (mathematics) fall short of meeting WP:FA? criteria? — Preceding unsigned comment added by AP295 (talk • contribs) 19:03, 10 February 2021 (UTC)

I'd much prefer making Addition a featured article. I actually used to edit a ton of Wikipedia math articles, and got a few to GA status. I thought I'd try a crack at a featured article. I got one reviewer who suggested reference changes. I made all those changes, then the FAC was rejected after 8 days because no one cared to review it. Honestly, that's one of the biggest reasons I stopped editing.

Anyway, addition should be much easier to get to FA status.Brirush (talk) 22:01, 11 February 2021 (UTC)

Most people know how to add and generally have a firm understanding of the concept. Certainly it's a worthy objective, but I'm mostly concerned about articles that the undergraduate student might depend upon, many of which are in pretty rough shape. I don't think silly stuff like the value of .9 repeating (which has a FA) or zero to the power of zero (see the section below) or division by infinity (above) provide as much value to the young student/scholar as a good Set (mathematics) article would, for instance. I admit I did not anticipate when I made this RfC that Mean and its related articles would together comprise such a nasty rat-nest of redundant and disorganized content, which nobody wants to touch, so perhaps Set (mathematics) would be a better place to start. AP295 (talk) 22:41, 11 February 2021 (UTC)

For Set (mathematics), the set operations should be explained much earlier than they are. The article has a lot of sections and it can probably be reorganized into fewer. The first image in the article is not particularly informative or instructive, and so I'd like to replace it with something a bit more useful. This article should not be hard to get to WP:FA status, most of the content is already there and with some adjustments it should be a great article. Unless anyone has a good plan for mean and its related articles, the set article will be a better warm-up. AP295 (talk) 15:43, 13 February 2021 (UTC)

WHAT SAY YOU? AP295 (talk) 02:11, 7 March 2021 (UTC)

I agree that the beginning of the article could be made accessible to a broader audience by giving some examples of sets and some examples of basic operations upon them, since there are 100 times more users who will want to understand sets at the grade-school level than who will want to know what extensionality means or what Russell's paradox says. I also agree that the first image is not helpful; maybe better would be a Venn diagram of two sets labelled A and B, with a few numbers in all four locations, and with the caption saying what $A\cup B$ and $A\cap B$ are? Or perhaps the two sets could be positive integers and even integers. Ebony Jackson (talk) 03:08, 7 March 2021 (UTC)

I'm not necessarily talking about WP:ONEDOWN. Most people learn about sets in college and it's fine to assume the reader has completed high school. I have no problem with including Russel's paradox and I don't think the article should belabor the easy stuff (e.g. by having too many examples). The set article is mostly just in need of reorganization and a few minor things here and there. Generally my concern is that many vital math articles remain underdeveloped. Some have too much content, some too little. Many of them are poorly organized. Some (e.g. M operator) have terrible notation or are just plain bad all around. AP295 (talk) 11:27, 7 March 2021 (UTC)

This page may be useful. However, it may be a little too big.--SilverMatsu (talk) 04:18, 7 March 2021 (UTC)

• For those who care, AP295 has now been indefinitely blocked. --JBL (talk) 19:16, 7 March 2021 (UTC)

  Having only seen this thread, that took an abrupt turn. — MarkH₂₁^talk 19:21, 7 March 2021 (UTC)

about Leibniz formula for π

I may have overlooked the explanation of the proof, but I remember this series convergence was subtle. Specifically, it seems that there is no explanation to Abel's theorem in the text of the proof. I feel like I learned this in complex analysis with Summation by parts and Abel's summation formula.--SilverMatsu (talk) 11:24, 7 March 2021 (UTC)

Just wanted to say the proof I remember also relies on Abel's theorem (or any variants). The proof given there looks ok, but I strongly suspect there is a complex-analysis proof that uses a usual trick of a contour integral. -- Taku (talk) 23:50, 8 March 2021 (UTC)

Thank you for your reply. I added this one.--SilverMatsu (talk) 08:03, 10 March 2021 (UTC)

Wolfram spam

Over the last month, a farm of sockpuppet accounts whose primary use was spamming and promotional editing associated with Stephen Wolfram. Many of the recent edits of the accounts have been reverted, and Blablubbs has expressed an interest in further cleanup. Since all of the accounts are several years old, I'm sure more assistance would be helpful. --JBL (talk) 20:41, 12 March 2021 (UTC)

Thanks JBL. Interested editors may also want to have a look at this COIN thread (permalink). Blablubbs|talk 20:43, 12 March 2021 (UTC)

For those who'd like to pitch in, the list of edits to be checked is here. (Just cross them off if they've been reverted or if they're unproblematic.) Thanks, JBL (talk) 22:59, 12 March 2021 (UTC)

Maybe this is a good time to consider whether many of our existing MathWorld links (often found in external link sections of articles) pass criterion 1 of WP:ELNO, that the link "should not merely repeat information that is already or should be in the article". (This is different from situations in which MathWorld is used as an actual reference, for which I think it can be acceptable and sometimes necessary but usually not the best choice.) —David Eppstein (talk) 01:48, 13 March 2021 (UTC)

Seems doubtful in most cases; I would support moving away from it as an external link. --JBL (talk) 02:28, 13 March 2021 (UTC)

Elementary cellular automaton

Entry Pascal's triangle of JBL's list contains two references to Wolfram. In § Overall patterns and properties, this appears as a normal reference (in fact, the only one of the whole section). So, if it is a Wolfram spam, the whole paragraph, and, maybe, the whole section must be removed. This needs a further study that is not the subject of this post.

The object of this post is § Elementary cellular automaton, that links heavily to Elementary cellular automaton, and its related articles Rule 30, Rule 90, Rule 110, Rule 184, and maybe others. All of this is based on a single self published Wolfram's primary source. I would incline to nominate all these article to AfD, but before that, it would be useful to have advices by people who know this kind of subject better. D.Lazard (talk) 09:38, 13 March 2021 (UTC)

"All of these articles"? Really? Did you not notice that Rule 90 and Rule 184 are Good Articles? All of these articles are definitely notable, despite the bad current sourcing for elementary CA. And elementary CA is one topic in mathematics that Wolfram really did make major contributions to; it is necessary to cite his works there (although we can and should of course cite others as well). —David Eppstein (talk) 16:59, 13 March 2021 (UTC)

Is left-to-right preference in European languages a POV?

At Row and column vectors an editor has commented on "carefully selected references" as expressing a point of view. Matrix transformations take a row vector on the left, or a column vector on the right, when acting for transformation. Using column vectors has subsequent transformations accruing to the left, something to be appreciated in right-to-left languages, but not in European languages. The references mentioned are geometers. Compounded transformation is common in modern geometry where group theory prevails, so the geometers avoid the reverse writing of transformations by using row vectors. A tag asserting the POV has been placed in the article, and discussion opened on its Talk. Rgdboer (talk) 03:28, 14 March 2021 (UTC)

• @Rgdboer: I'm not sure what your post is asking for here? Ebony Jackson had opened a talk page section at Talk:Row and column vectors#Preferred input vectors for matrix transformations. I agree with EB that considering the action of matrices on column vectors from the left is a more common convention than their actions from the right. I also agree with the older comment from JayBeeEll at Talk:Row and column vectors#Right-to-left script that the material claiming the fact that directionality of English text is left-to-right has led some English authors to have a preference for the row vector input to matrix transformation is unreferenced and probably WP:OR. — MarkH₂₁^talk 08:47, 14 March 2021 (UTC)

Soumitra Kumar Mallick

The article Soumitra Kumar Mallick could use some expert attention. Right now, all its citations are not independent of the article's subject, but even if one were to disregard that concern, it's puzzling that his resume on the website of the Indian Institute of Social Welfare and Business Management claims the following achievements:

"Millenium Mathematics Prizes for solution of P Vs. NP problem with New Ecommerce Field with self energy and Artificial Intelligence with SO(32) String Matching Field Theory Higgs-Englert-Bosonic Mechanism (leading to the Development of Quantum Mathematics and Ramanujan-Hardy-Mallick- Hamburger- Mallick Functor Algebra Calculus (Tool Area)). [...] For solution to all Millenium and Clay Research Award problems for AGGNNNetworks with [.. some coauthors...] using RHMHM Functor Algebra Calculus and acknowledged by ResearchGate and referees."

Unfortunately I'm kind of rusty on Ramanujan-Hardy-Mallick-Hamburger-Mallick Functor Algebra Calculus myself, but it seems kind of odd to me that the Clay Institute's page for the P vs NP Millennium Prize Problem still shows it as unsolved right now.

I am also pinging User:DMySon, who created the article (including the claim that Soumitra Kumar Mallick has won a Millenium Mathematics Prize.)

Regards, HaeB (talk) 15:14, 15 March 2021 (UTC)

It was vandalized by a bunch of IP-address editors. I reverted to a better version and semiprotected. It is still a seriously problematic article, but at least not blatantly false. —David Eppstein (talk) 16:48, 15 March 2021 (UTC)

Thank You HaeB, for my attention. I found the Millenium Mathematics Prize claimed on (Indian Institute of Social Welfare and Business Management) [2]. At the time of writing i added most of the information on the basis of IISWBM. However, i also couldn't found any solid references. The prize and other edits done by ip address have been undone and page is semi protected by David Eppstein, Thank You for your help. DMySon 17:35, 15 March 2021 (UTC)

No independent sources, few citations, and claims of proving their own claim of proving P vs. NP aren't sufficient for notability. Nominated at AfD here. — MarkH₂₁^talk 19:08, 15 March 2021 (UTC)

Relevant Peer review

Hi all, the nominator at Wikipedia:Peer review/Matchbox Educable Noughts and Crosses Engine/archive1 has requested comments "especially on the mathematical front". Members of this project may be interested in taking a look. Eddie891 ^Talk _Work 01:33, 16 March 2021 (UTC)

Square brackets notation for quadratic fields

Could someone more confident and competent on the topic than I -- i.e. almost anyone here, I'd presume -- comment over at Talk:Bracket (mathematics)#Square brackets for quadratic fields? on whether that usage would be worth adding to the article, and if so in what form? 109.255.211.6 (talk) 10:53, 14 March 2021 (UTC)

I added a new section at Bracket (mathematics) to explain this. Ebony Jackson (talk) 14:02, 14 March 2021 (UTC)

Great work! Many thanks. 109.255.211.6 (talk) 05:24, 16 March 2021 (UTC)

Notation for partially solved multiple integrals

I spotted this in Planar lamina:

$M_{y}=\int _{0}^{2}{\int _{x}^{4-x}}{}{}x\,(2x+3y+2)\,dy\,dx$

$M_{y}=\int _{0}^{2}\left.\left(2x^{2}y+{\frac {3xy^{2}}{2}}+2xy\right)\right|_{x}^{4-x}\,dx$

$M_{y}=\int _{0}^{2}(-4x^{3}-8x^{2}+32x)\,dx$

$M_{y}=\left.\left(-x^{4}-{\frac {8x^{3}}{3}}+16x^{2}\right)\right|_{0}^{2}$

$M_{y}={\frac {80}{3}}$

My concern is the high vertical line on the right side. While it is quite obvious in a case of a single-variable integral, I suppose in this case it may be somewhat confusing for readers not familiar with multiple integrals. The problem may arise: which variable should I apply the limits to?

I'd like to add the specific variable indication, like below (in red). Is it acceptable?

$M_{y}=\int _{0}^{2}\left.\left(2x^{2}y+{\frac {3xy^{2}}{2}}+2xy\right)\right|_{{\color {red}y=}x}^{4-x}\,dx$

$M_{y}=\left.\left(-x^{4}-{\frac {8x^{3}}{3}}+16x^{2}\right)\right|_{{\color {red}x=}0}^{2}$

CiaPan (talk) 12:52, 16 March 2021 (UTC)

Yes. --JBL (talk) 14:23, 16 March 2021 (UTC)

This notation is acceptable, but such a succession of formulas without any prose is not. So, it would be better to write "the value of the internal integral is ...; putting this result in the double integral gives thus ...". Such a split of the computation makes reading much easier. This would also avoid to have a vertical bar inside an integral; This may be confusing, although formally correct with your sggestion applied. D.Lazard (talk) 14:43, 16 March 2021 (UTC)

@D.Lazard: Thank you for the hint. I think you're right, but I need to find some more time to do it. (Or, may be, someone else will do that in a meantime.) Anyway, I think the detail I propose will still be useful for the expansion of the internal integral (i.e., at the point where you used dots for the first time), because there are both x and y in the same expression there. --CiaPan (talk) 15:53, 16 March 2021 (UTC)

@JayBeeEll and D.Lazard: Thank you both, I have made the described change (without the red color ). The result can be seen here: Special:PermaLink/1012477511#Example. --CiaPan (talk) 16:04, 16 March 2021 (UTC)

By the way, the second reference seems to link to the top page. The title seems to be entered correctly, but I don't know why. --SilverMatsu (talk) 15:24, 16 March 2021 (UTC)

@SilverMatsu: Wow, well spotted. Apparently I didn't test it carefully enough. I thought the 'title' parameter to the {{MathWorld}} template is enough if it's same as 'id', but I was wrong. Fixed now: Special:Diff/1012473537. Thank you--. CiaPan (talk) 15:37, 16 March 2021 (UTC)

Thank you for the fix and teach. I was able to learn about templates in your reply.--SilverMatsu (talk) 16:01, 16 March 2021 (UTC)

@SilverMatsu: So I suggest you learn {{Reply to}} template next. It's often used at talk pages to notify (a.k.a. 'ping') other users, as I did in this reply. You may also make some fun of exploring {{Smiley}}. CiaPan (talk) 16:20, 16 March 2021 (UTC)

But that's completely unrelated topic, so if you need to ask some questions, I encourage you to visit our WP:Teahouse, or – for more technical and Wikipedia-focused questions – an appropriate section of WP:Village pump. --CiaPan (talk) 16:23, 16 March 2021 (UTC)

Formal mathematical language versus informal intuitive language

I noticed that recent edits to Set (mathematics) have removed some of the informal, non-mathematical comments, which were intended to help a layman Wikipedia reader to understand the subject matter. I am doubtful this is in accordance with Wikipedia principles. --Jonathan G. G. Lewis 00:33, 20 March 2021 (UTC)

Maybe I made some of these edits you are talking about? For me it was not about formal vs. informal, but just about clarifying and simplifying the wording; maybe I failed in some cases. In fact, I was trying to make it less technical in places by moving jargon such as "intensional definition" and "ostensive definition" further down in the article. In any case, I would be happy to discuss any of the edits at Talk:Set (mathematics). Ebony Jackson (talk) 01:54, 20 March 2021 (UTC)

about the priority scale of complex analysis

Apparently it was changed by the automated rater. I'm trying to re-evaluate the priority scale, but I can't seem to decide.--SilverMatsu (talk) 15:52, 20 March 2021 (UTC)

If you check the criteria for priority evaluation here, Complex analysis has significant impacts on other fields (engineering, physics) and is pretty important within mathematics also, so it qualifies as High priority. I'll update it now.Tazerenix (talk) 00:06, 21 March 2021 (UTC)

How to cite BAMS New Series

See also: Wikipedia talk:WikiProject Mathematics/Archive/2017/Dec § Annals of Mathematics Second Series citations (and other similar cases)

There are several citations to BAMS in a weird format

• |journal=American Mathematical Society. Bulletin. New Series (used at least 44 times)
• |journal=Bulletin (New Series) of the American Mathematical Society (used at least 13 times)

Would it be OK to normalize both to journal=Bulletin of the American Mathematical Society |series=New Series? Headbomb {t · c · p · b} 01:10, 17 March 2021 (UTC)

The normalization seems fine to me. I wasn't even really aware that there was a new series (it seems that the old series only ran from 1891–1894, ending even before the Annals first series).— Preceding unsigned comment added by MarkH21 (talk • contribs) 04:54, 17 March 2021 (UTC)

Anyone else? I'd like to clean this up by the end of the week. Headbomb {t · c · p · b} 01:33, 25 March 2021 (UTC)

Definitely should be |journal=Bulletin of the American Mathematical Society, with or without |series=New Series. The first "weird" alternative is what you get from the BibTeX from MathSciNet in the FJOURNAL (full journal name) field; many journals are order. in the wrong. with periods. like that. The other alternative you're likely to see from the same source is their abbreviated format, "Bull. Amer. Math. Soc. (N.S.)". Instead, zbMATH lists them as "Bull. Am. Math. Soc., New Ser." If you see any of those, they should be converted to the spelled-out title, I think. —David Eppstein (talk) 01:43, 25 March 2021 (UTC)

Alright, setting User:JCW-CleanerBot on it. Headbomb {t · c · p · b} 19:08, 25 March 2021 (UTC)

Expansion in Planar lamina

I have added some prose to Planar lamina#Example, as User:D.Lazard suggested in the previous thread (now archived at Wikipedia talk:WikiProject Mathematics/Archive/2021/Mar#Notation for partially solved multiple integrals). IMHO it still doesn't look like an encyclopedic article, but I hope it's at least a bit easier to read now. Any comments are welcome, as well as necessary fixes to spelling, grammar or layout. --CiaPan (talk) 09:44, 26 March 2021 (UTC)

It may be a bit off topic, but I think improving iterated integrals can help explain this article. The contents of the Order of integration (calculus) are likely to help improve.--SilverMatsu (talk) 15:41, 28 March 2021 (UTC)

Apr 2021

Cleanup of articles on algebras

It seems to me that the articles on algebra over a field, associative algebra and non-associative algebra could use a thorough workover and possibly a merge.

The article on non-associative algebras says that '"non-associative" means "not necessarily associative"' (rather than "not associative") – but then it's not clear why this article is distinct from algebra over a field, which is also about algebras that "may or may not be associative". The sentence "The multiplication operation in an algebra may or may not be associative, leading to the notions of associative algebras and nonassociative algebras." in algebra over a field seems to imply that "non-associative" does mean "not associative".

Constructions such as quotients and products are briefly listed in associative algebra, but no reason is mentioned why these should require associativity; they're not mentioned in the more general articles. The most detailed discussion of direct sums and products of algebras in fact appears to be in yet another article on the direct sum of modules. This warns of a terminological pitfall that the articles on algebras don't mention.

In algebra over a field, the field is in the title and there's a section near the end on the generalization to algebras over a ring. In associative algebra, the introduction starts out saying that an algebra is over a field but the definition section uses a ring instead. In non-associative algebra, a field seems to be assumed, but there's no definition section and the introduction is very similar in this respect to the one in associative algebra.

Quite generally, it feels as if a lot of the content is spread somewhat randomly among these three articles. There should either be a single article about algebras, or, if associative algebras deserve an article of their own, that article should concentrate on the features that depend on associativity, and presumably general things like products and quotients should be in the general article.

(I don't want to do this myself since my understanding of algebras is somewhat superficial.)

Joriki (talk) 19:29, 28 March 2021 (UTC)

One more thing: There's also an article algebra homomorphism, to which both algebra over a field and associative algebra refer as a "main article", even though it assumes associative algebras. The article on non-associative algebras doesn't mention homomorphisms.

Joriki (talk) 19:36, 28 March 2021 (UTC)

Further information about products of algebras is spread over tensor product of algebras and free product of associative algebras.

Joriki (talk) 20:44, 28 March 2021 (UTC)

I agree that the contents of non-associative algebra should be merged into algebra over a field (and reworked, in some cases also trimmed). The article about associative algebras does have a bit of an overlap, but also a lot of content that is special, so these I wouldn't merge. I suggest merging algebra homomorphisms into ring homomorphisms. Tensor product of algebras deserve their own home. The free product of associative algebras is a bit of a stub right now, but I think it makes sense to keep it separately. Jakob.scholbach (talk) 11:28, 1 April 2021 (UTC)

Weird recommendations in MATLAB article

Some Mathworks employees have been making suggestions about the MATLAB page recently, but not directly making edits, in order to maintain neutrality.

One pointed on that page's talk page that the 'list of alternatives' on the MATLAB page is kind of weird. It's unsourced and is basically just a list of recommendations, which I'm pretty sure should be covered under one of the list of things Wikipedia is not.

On the one hand, I can see how this directly benefits the corporation, which is suspicious. On the other hand, I really don't think that kind of list is appropriate in an article. We don't have a list of alternatives for Adobe Photoshop, despite its awful business practices, or McAfee VirusScan, despite its shady nature.

I'd suggest removing that section or replacing it with something sourced (perhaps a review article describing commonly used mathematical languages). As it is, I don't think it should remain in its current form. I wanted to check in here before doing anything, but if people don't seem interested in discussion, I'll just remove it after a day or two. Brirush (talk) 04:25, 1 April 2021 (UTC)

Yes, definitely trim it to something sourced. There are plenty of sources discussing alternatives. Dicklyon (talk) 04:59, 1 April 2021 (UTC)

Okay, I removed the big recommendations section and replaced it with a sourced paragraph listing some popular tools. As always, anyone's free to edit and improve. Brirush (talk) 22:05, 1 April 2021 (UTC)

How to add external interactive animations about some Math subject

I see that some mathematical subjects benefit immensely of animations and in particular interactive ones. How can we make possible to link those animations to an specific article? Would it be via external links? — Preceding unsigned comment added by Ninguem wiki (talk • contribs)

For background on this question, see Talk:Taylor_series#New_external_link and User_talk:DVdm#Reversion_on_the_Taylor_Series_page. --JBL (talk) 16:30, 2 April 2021 (UTC)

Looking at Commons:Project scope/Allowable file types the best you could do is a some kind of animation. There is mw:Extension:Graph which allows quite complex graphs which can be interactive. There are some Demos which are could be adapted to fit. Examples of using this extension can be found at Category:Pages using the Graph extension. --Salix alba (talk): 17:38, 2 April 2021 (UTC)

Thank you for the reply. Based on Talk:Taylor_series#New_external_link and User_talk:DVdm#Reversion_on_the_Taylor_Series_page seems that a common user can't contribute with an interactive animation. As pointed in the discussion I had with the other users, any contribution is to be considered non-reliable if it comes from a common user. I'd interested in knowing what is the difference between a written contribution in an article (writing, editing, etc) and an external contribution (in a form of a link to a page with no advertisement and following all the rules). I have a contribution which I would like to share in Wikipedia because I thick its valuable for understanding of the topic (see discussion mentioned above). How can I reach a consensus on it? Is THIS the right forum? In my understanding the page itself was the right forum so I insisted on keeping the link until someone accesses it and started a discussion wether it is valuable or not. Please notice that the contribution does not have any affiliation, propaganda, logo, advertisement of any kind. Its a simple plain interactive animation. Since you are an organised group and decided to support each others view, how can I reach a consensus? If its a consensus that the page is not the right place to discuss, I stoped posting there and Im bringing the discussion here. It would be very good if User:DVdm and the others could participate.Allan Martins (talk) 20:05, 2 April 2021 (UTC)

Answering to talk:Salix alba, thank you for the answer. I have already a complex Javascript interactive animation, the question was more on the sense of wikipedia rules. See first reply above.Allan Martins (talk) 20:06, 2 April 2021 (UTC)

Wikipedia cannot allow any user to add random JavaScript to articles, that would be a security nightmare. You can modify your personal JavaScript, at Special:MyPage/vector.js but that will not be seen by other users. The graphs package is the only way you can get interactivity. --Salix alba (talk): 20:50, 2 April 2021 (UTC)

I agree with you and understand that Javascript on Wiki pages is far too potentially harmful. That is exactly why I want to contribute by placing all in an external link and adding it as an external link. You suggestion on the graph package is very interesting though, I'll take a look to try other contributions. Allan Martins (talk) 22:51, 2 April 2021 (UTC)

What I don't understand is how can we incentive people to contribute if they additions of a simple external link is not cordially analysed and simply reverted by the interpretation of the rules. The link Im providing is absolutely in accordance will all WP:External_links except that we didn't reach a consensus on the WP:Reliable_sources. But I'm willing to discuss it and try to show, in a consensus, that the link I'm providing is no different than an edit that people like me (a professor) would do in an article to contribute. I'm not sure if people even bother to take a look at the link and see that its in accordance with WP:External_links policies. There is no advertisement, not even the name of the author is promoted there. I'm don't know why people think I gain in insisting on doing this contribution. I'm a professor and credentials are not relevant here, but my job is to educate people and Wikipedia is a very powerful tool for it. I would understand the argument that "if everyone start putting links, it would be a mess". But so is "if everyone start editing pages would be a mess". Thats the whole point of Wikipedia. it works! So, I'm pretty sure if I was just practicing vandalism in trying to place one harmless (on the contrary, useful) link to an article I would not wasting my time here explaining everything. So I ask people that read this discussion (not specifically you talk:Salix alba since your answer was very productive for me showing me the graph functionality) to take a moment to reflect on their actions. Impose wikipedia rules just the bold "letter" of it is not ok. That is to ignore the true principle behind Wikipedia. Wikipedia is NOT a place where you have fun catching "bad edits". It has a serious goal of promoting knowledge and disseminate information. And mainly, to stimulate and encourage contributions. Im just starting to contribute and, honestly that was not a nice welcome. You can't use people's serious contribution to collect patrol points or satisfy some personal vanity. Let's discuss. Present arguments that sustain your interpretation of the rules.Allan Martins (talk) 22:51, 2 April 2021 (UTC)

I'm sorry for the heavy text above, but I like Wikipedia a lot. I feel its worth fight for its correct use.Allan Martins (talk) 22:51, 2 April 2021 (UTC)

Blackboard bold (again)

Our discussion from November 2020 has been reopened at Wikipedia talk:Manual of Style/Mathematics#Blackboard bold. D.Lazard (talk) 11:19, 24 March 2021 (UTC)

Indeed, on a white background, blackboard bold seem difficult to read. If we would like to deprecate blackboard bold, I think it would be useful to change the extension math so that we can type \Complex and display $\mathbf {C}$. For example, in Complex analysis and Several complex variables, even if I stopped using blackboard bold, the meaning seemed clear. White letters on a black background are personally easy to read, but the blackboard bold is a bit hard to read because I can't change the background color.--SilverMatsu (talk) 15:33, 24 March 2021 (UTC)

What does mean difficult to read? Do you mean read or distinguish from anything else? If you have difficulties to read $\mathbb {C}$, you must also have difficulties to read most characters, including $\mathrm {C} .$ If, by "read", you mean "distinguish", it seems that $\mathbf {C}$ has much more problems, at least outside complex analysis. For example, many authors use boldface for denoting vectors and matrices. In this case, one has to look to the context for distinguishing, in a formula, a matrix from the complex numbers. The great advantage of blackboard is to be definitely not ambiguous. Another example: If you read $\mathbf {R} [x],$ you have to look at the context to know whether this is the polynomial ring over the reals or over an arbitrary ring, while $\mathbb {R} [x]$ is definitevely not ambiguous in any context, and more specially in a context that is not specially about the reals (for example in mechanics). So I strongly oppose to deprecate blackboard bold. I oppose also to change the rendering of \complex, as this would automatically change many articles without any consensus of their editors. D.Lazard (talk) 09:13, 25 March 2021 (UTC)

Thank you for the reply. I agree that blackboard bold is clearer, and my comment is based on the assumption that blackboard bold would be abolished, so thank you for your advice. The meaning of difficult to read is a little dazzling on the display, but I was taught at the tea house that the colors can be reversed.--SilverMatsu (talk) 13:29, 26 March 2021 (UTC)

---

My eyes are bad, but i can read black blackboard bold on white background without any difficulty.

I totally agree with D.Lazard's whole reply.

Sorry, SilverMatsu! :-)

RavBol (talk) 00:04, 4 April 2021 (UTC)

In fact, I don't think anyone at Wikipedia talk:Manual of Style/Mathematics#Blackboard bold was recommending deprecating blackboard bold! Maybe this was a misunderstanding. Anyway, it seems to be straightened out now. Ebony Jackson (talk) 03:16, 4 April 2021 (UTC)

Currently, I can invert colors using gadgets. Thank you for your concern:) It seems that I overlooked that the style manual had changed (I thought blackboard bold was not recommended on wikipedia.). But the extension:math outputs as an image, so I'm not sure how it affects the reading software. Also, since Unicode characters cannot be used for blackboard bold, I am wondering what to do when using it for the section title. The link I showed used two different notations. If possible, I'm thinking of using one notation. The main reason I decided to comment here was to get advice on the pages shown in the links.--SilverMatsu (talk) 15:44, 4 April 2021 (UTC)

Induced metric

Does anyone know offhand of a good reference to add to Induced metric? The reason for the "expert needed" tag is technically untrue (one reference exists rather than zero), but an additional pointer couldn't hurt. XOR'easter (talk) 15:50, 4 April 2021 (UTC)

This is a fairly basic concept that is discussed in textbooks on manifolds. For instance, see pages 25-27 of Lee, John M., Riemannian Manifolds: An Introduction To Curvature, (GTM no. 176, Springer,1997)(ISBN 038798271X). --{{u|Mark viking}} {Talk} 17:42, 4 April 2021 (UTC)

about Plurisubharmonic function

Regarding section Oka's theorem, the content of the theorem seems correct (since the article name is a plurisubharmonic function, there is no need to use the term pseudoconvex domain.), but I have doubts about calling the content of this section Oka's theorem. (also, I think the prove to $\mathbb {C} ^{n}$ space was the IX'th Oka's paper in 1953.) There is no doubt that it was Kiyoshi Oka who solved Levi's problem for $\mathbb {C} ^{n}$ space (Riemannian domain), but it was Cartan who extended Levi's problem for Stein manifolds, which is written on this article and it seems like Grauert prove that. I'm wondering if Levi's problem with Stein manifolds should be included in Oka's theorem. I'm not sure about this because I just called it Levi's problem. thanks!--SilverMatsu (talk) 15:00, 5 April 2021 (UTC)

Good edit?

Did this edit fix an error, or introduce one? Maths articles can be quiet, and problems might linger unnoticed; this seemed like the best place to ask. Cheers, BlackcurrantTea (talk) 10:21, 10 April 2021 (UTC)

Looks good to me: a function of s is integrated over the range s=0 to s=t. However, you're right in principle that lots of superficially similar edits are mistakes or subtle vandalism, both of which need to be reverted. Certes (talk) 11:06, 10 April 2021 (UTC)

It's those mistakes or subtle vandalism I fear I'd miss in this area. Thanks for taking a look at it. BlackcurrantTea (talk) 14:34, 10 April 2021 (UTC)

Typesetting \mathbb{1} within Wikipedia articles

How can I use 𝟙 in a math equation? It seems from various sources that I need to use the bbm package. Is it possible to use LaTeX in Wikipedia articles that use packages? --Yoderj (talk) 13:37, 9 April 2021 (UTC)

I have used some funny business in the Heaviside step function article:

<big>𝟙</big><math>\,\!_{x > 0}</math>

but there must be a better way --Yoderj (talk) 13:45, 9 April 2021 (UTC)

I asked this question over at the help desk and Mike Turnbull guided me here:

Hi Yoderj. You should be able to get some guidance at WP:LATEX. Alternatively, seek out the Talk Pages for the maths projects and an expert in this stuff will likely help. Mike Turnbull (talk) 15:16, 9 April 2021 (UTC)

Thanks! --Yoderj (talk) 18:38, 9 April 2021 (UTC)

I've created a phabricator task. T279805. --Salix alba (talk): 19:31, 9 April 2021 (UTC)

Looks like its upstream, and the syntax does not work in standard mathjax. It might be possible to add one of the packages mentioned in the stack exchange thread. --Salix alba (talk): 19:44, 9 April 2021 (UTC)

For an indicator function, I'm sure this isn't the answer you wanted, but I would suggest using a plain $1$ or bold $\mathbf {1}$ which are more common notations than blackboard bold in this context. (I don't mean to detract from your technical typesetting question which is interesting in its own right and I hope will be resolved.) Adumbrativus (talk) 19:48, 9 April 2021 (UTC)

I agree with Adumbrativus. --JBL (talk) 19:55, 9 April 2021 (UTC)

A bold one it will be. Thank you. --Yoderj (talk) 22:05, 9 April 2021 (UTC)

So are there any cases where we would want this notation? Getting something through code review is a lot of work for something which might not be used. --Salix alba (talk): 15:36, 10 April 2021 (UTC)

Script to show short descriptions in Wikipedia categories

I'd like to call attention to a user script that has been developed to show WP:Short descriptions in category listings: User:SD0001/shortdescs-in-category

This might be of particular interest to mathematics users as categories of mathematical theorems typically show titles of the form "So-and-so and Other-person theorem," i.e. just the names of discoverers, which conveys little or no information about the result proved (or conjectured). When this script is installed and the Show SD button that appears is clicked, any short description associated with an article title is displayed beneath it. To the extent that these SDs are available and informative, it becomes much easier to understand the content of a theorem category.--agr (talk) 17:54, 14 April 2021 (UTC)

@ArnoldReinhold: Neat! — MarkH₂₁^talk 18:00, 14 April 2021 (UTC)

New promotional math articles

Editors may want to monitor the flurry of new math articles by Remitbuber, including Math crisis, Adrián Macías, Blas Méndez, Virus Matemático, General Assembly of the International Mathematical Union, ICM 1966, ICM 2014, ICM 2026. Many do not seem notable and may involve a fair amount of COI. — MarkH₂₁^talk 20:35, 14 April 2021 (UTC)

Nicolás Atanes was also very promotional when first created; it's now been stubbed down (and is still not a good article but at least is not overwhelmed with promotionalism). [Of course you MarkH21 know this, since you did much of the cleanup.] Most of these topics are closely related to Atanes, suggesting paid editing or at a minimum a serious COI. Probably worth a trip to WP:COIN. --JBL (talk) 22:01, 14 April 2021 (UTC)

@JayBeeEll: In fact, someone has since taken this to ANI: Wikipedia:Administrators' noticeboard/Incidents#User:Remitbuber! — MarkH₂₁^talk 22:05, 14 April 2021 (UTC)

Math crisis has been BOLDly redirect to Math anxiety. One of the remaining articles is now at AfD: Wikipedia:Articles for deletion/Adrián Macías. — MarkH₂₁^talk 13:29, 15 April 2021 (UTC)

@MarkH21: If Math crisis isn't noticeable, I'd suggest AfD instead of redirects. See the Foundations of mathematics lead statement.--SilverMatsu (talk) 15:01, 15 April 2021 (UTC)

by the way, the story changes but, I happened to see Math anxiety with redirects. I thought Hereditary Genius and American math education were over-summarized. Hereditary Genius was later added and summarized. Therefore, although it has references, it does not seem to have much to do with the referenced books and treatises. --SilverMatsu (talk) 23:35, 18 April 2021 (UTC)

Is it better to avoid just writing domain in articles?

Complex analysis articles sometimes say open connected set, is this better than writing domain alone?--SilverMatsu (talk) 08:57, 17 April 2021 (UTC)

Using domain seems correct, and may lead to a simpler (and thus clearer) formulation. However, we have several articles on related sorts domains (some of them being not listed in Domain (disambiguation)): Domain of a function, Domain of definition, Domain of holomorphy, Natural domain, and maybe others that I have not identified, and some that are lacking (Domain of continuity, Domain of differentiability, Domain of smoothness, ...). My suggestion is to merge all these articles into Domain of a function or Domain (mathematical analysis). I have not a clear opinion whether these two articles should be merged. A possibility would be to redirect Domain of a function to function (mathematics), with a clear link in the lead of the new Domain (mathematical analysis). D.Lazard (talk) 09:56, 17 April 2021 (UTC)

There is value in cleaning up the terminology, to make it less confusing. There is also value in using the same terminology as other sources (even before we bring Wikipedia policy into it). How about explicitly stating which meaning of "domain" is meant, at the first use in the article? And the correct wikilink might suffice for that. Mgnbar (talk) 14:03, 17 April 2021 (UTC)

Thank you for your reply. D.Lazard's advice will take some time, but I think we can clearly formulate the domain. but, I don't think we have to merge. Even if the content is duplicated, I think it is okay to write what is written on the branch again on the trunk. In other words, improve Domain (mathematical analysis) based on your ideas and and think about merge as another discussion. As another topic, I think that complex analysis can be improved based on such an idea. Of course, I will try to be as concise as possible ... On the other hand, Mgnbar's idea is that it can be implemented immediately. Already, domain has been used for various articles, and the articles need to be improved immediately. On wikipedia, we can't expect to read all the articles from top to bottom, so we probably need to include that in article lead. Conversely, if we can't include it in we lead statement, you probably need to improve that lead statement. thanks!--SilverMatsu (talk) 00:02, 19 April 2021 (UTC)

Minimal polynomial of 2 cos(2π/n)

The formatting of the title of Minimal polynomial of 2cos(2pi/n) is abominable, and the DISPLAYTITLE template didn't help. How to proceed? Michael Hardy (talk) 00:11, 11 April 2021 (UTC)

The present title is not only not convenient for a good display, it is also not convenient from an encyclopedic point of view: Viewing this title, a reader should naturally ask the question "Why considering specifically these numbers". So, I suggest to rename the article Real parts of roots of unity. One may object that this article is not about the the real parts, but about twice the real parts, but the difference is small enough for not being confusing.

Another question is whether this article should be merged into Cyclotomic polynomial. D.Lazard (talk) 09:48, 11 April 2021 (UTC)

Merging it into Cyclotomic polynomial, perhaps into a section entitled "Related polynomials", sounds like a good idea to me. Ebony Jackson (talk) 02:45, 13 April 2021 (UTC)

That seems plausible to me also, although I also like D.Lazard's suggestion for a better title. Something I wonder in thinking about this possible merge: the article states that these polynomials can be expressed either in terms of the cyclotomic polynomials or the Chebyshev polynomials, so I would think this also means that the cyclotomic and Chebyshev polynomials can be related by transitivity. But currently neither the cyclotomic polynomial nor the Chebyshev polynomials article mentions the other. Should they? —David Eppstein (talk) 06:46, 13 April 2021 (UTC)

Requested move opened. The current title should not be kept as a redirect, regardless of whether this article should be merged into another. –LaundryPizza03 (dc̄) 13:16, 25 April 2021 (UTC)

A cube, but with rhombuses for faces

On first glance the articles Rhombohedron and Trigonal trapezohedron are about the exact same object (the equilateral parallelepipeds). Before I start a merge discussion, I was hoping someone else would check that I'm not missing some meaningful subtlety. --JBL (talk) 15:18, 24 April 2021 (UTC)

@JayBeeEll: By the descriptions in Rhombohedron#Special cases by symmetry, it looks like a trigonal trapezohedron is a type of rhombohedron where all of its faces are necessarily congruent. — MarkH₂₁^talk 16:26, 24 April 2021 (UTC)

[ec] The difference appears to be that in rhombohedron the rhombi can be of three types, in three opposite pairs, but in trigonal trapezohedron they're all the same as each other. But as usual the "related polyhedra" section of the trigonal trapezohedron article looks mostly off-topic and removable. —David Eppstein (talk) 16:28, 24 April 2021 (UTC)

Great, thanks both -- I knew I must be missing something. David, indeed. --JBL (talk) 14:04, 26 April 2021 (UTC)

Group (mathematics) Featured article review

User:Graham Beards has nominated Group (mathematics) for a featured article review here. Please join the discussion on whether this article meets featured article criteria. Articles are typically reviewed for two weeks. If substantial concerns are not addressed during the review period, the article will be moved to the Featured Article Removal Candidates list for a further period, where editors may declare "Keep" or "Delist" the article's featured status. The instructions for the review process are here. SandyGeorgia (Talk) 16:01, 26 April 2021 (UTC)

May 2021

about Function (mathematics)

I was confused about the redirect f(x). (About the ambiguity that appears at the beginning of the function article by redirecting to the function.) The girls group seems like Abelian groups, Lie groups and Galois groups, but they were actually music artists. Personally, I think the function is just f. We might think this is a Dynamics (music) forte. I would like to know what kind of rules an artist has when he uses the theorems and symbols that are often used in mathematics as a respect for mathematics. (This is a rule about article names on wikipedia. Duplicate with the following sentence) If artists add the theorems and symbols commonly used in mathematics to their group (does not Group (mathematics)) names as a respect for mathematics, do they need to be reflected in mathematics articles?--SilverMatsu (talk) 22:56, 21 April 2021 (UTC)

I'm confused about what you're trying to ask. But I suspect that in this case the musicians are the ones that meet WP:COMMONNAME (especially because that's their main name, not an alternative name for them) and that the redirect and hat should go the other way. —David Eppstein (talk) 00:53, 22 April 2021 (UTC)

Thank you for your reply. The main confusion I had was that the Function (mathematics) would show the music artists, so if we redirect f(x) to the music artists, that's fine. My other question is, if artists, etc. use math-related terms (f(x) this time) in their names, do they need to write in the math article? (function this time) Also about name priority, but this time redirecting f(x) as a music artist was a solution as we didn't have to write about the music artist in the function.--SilverMatsu (talk) 01:26, 22 April 2021 (UTC)

If we determine that the primary meaning of "f(x)" is the musicians, then we should move the article to that name, not redirect that name to the article. —David Eppstein (talk) 01:36, 22 April 2021 (UTC)

Thank you for your reply and advice. Certainly it seems that we need to consider moving pages as well. I think that the meaning of f (x) is most often used as a function and has a long history, but when we would like to refer to an article function, we probably don't look up f(x). Rather, in a math article, are you trying to refer to another article? When asked, it's strange to move away from articles in the field of mathematics. In fact, I thought it was about math, so I thought of the girls group as a new group by group theory. (This my misunderstanding is a embarrassing.) I was able to confirm whether wikiproject:mathematics needed the article name f(x), apparently, so it seems necessary to leave it to another wikiproject. The math article showed a music artist, so I was very confused about where to consult. After that wikiproject:music?--SilverMatsu (talk) 02:15, 22 April 2021 (UTC)

Someone who puts "f(x)" into the search bar is someone who is looking for information about something called "f(x)". If you pick up any calculus textbook, you will see hundreds of equations that contain the expression "f(x)", and the article Function (mathematics) is the obvious starting point for gathering information about what this means. If you already know that the article Function (mathematics) is the correct starting point for finding information about this topic, you would not use this redirect, but so what? I think you are not considering broadly who is served by navigational aids like this. --JBL (talk) 12:53, 22 April 2021 (UTC)

Looking at the corresponding talk page, it seems good to move if there is no problem from the viewpoint of mathematics. The f (x) link doesn't seem to be a problem either. Therefore, if there is no objection on this page(discussion), it seems good to move.--SilverMatsu (talk) 07:32, 22 April 2021 (UTC)

I started the discussion. The article itself doesn't seem to be related to mathematics, but you might be interested in discussing the meaning of f (x).--SilverMatsu (talk) 11:16, 22 April 2021 (UTC)

Apparently there was a no consensus to move to the musical group. (Thanks to D.Lazard). Thank you for participated in the discussion.--SilverMatsu (talk) 15:05, 1 May 2021 (UTC)

Proposal: move(Change the article name) Several complex variables to Function of several complex variables

The following discussion is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

---

This is a complex variable in Talk:Complex analysis and has been discussed. For the one complex variable, it seems like a section redirect to Complex functions(in complex analysis), then, the pair seems like Functions of several complex variables. Also, the article names of Several real variables are Function of several real variables. thanks!--SilverMatsu (talk) 04:49, 11 March 2021 (UTC)

• To clarify, this is what you are proposing:
  • Retarget: Complex variable → Complex analysis#Complex functions
  • Redirect Complex variables → Function of several complex variables
  • Move: Several complex variables → Functions of several complex variables
  • Keep: Several real variables → Function of several real variables
  Is that correct? — MarkH₂₁^talk 05:00, 11 March 2021 (UTC); add "Complex variables" to the list 06:34, 11 March 2021 (UTC)

Thank you for clarifying. sorry, I made a misspelling. But also include Retarget changes in the proposal. The correct spelling is Complex variables.(This seems to be a separate page from the complex variable.)--SilverMatsu (talk) 05:17, 11 March 2021 (UTC)

So also add "Redirect Complex variables → Function of several complex variables" to the list above? — MarkH₂₁^talk 05:44, 11 March 2021 (UTC)

Thank you for your help. I was a little confused because I didn't think it was another page without the s(I overlooked complex variable), but I realized it would be better to add the idea you proposal.--SilverMatsu (talk) 05:57, 11 March 2021 (UTC)

• Support (with two modifications): The proposal looks reasonable to me. The proposed organization clarifies the relationship between the subjects and are also common in the literature. I would probably leave Complex variable as it is, since theory of functions of a complex variable is bolded as an alternative term in the first sentence at Complex analysis. I would also retarget Real variables → Function of several real variables. — MarkH₂₁^talk 06:39, 11 March 2021 (UTC)
• SupportTazerenix (talk) 07:11, 11 March 2021 (UTC)
• Support (Including modifications to two proposals by MarkH21.)--SilverMatsu (talk) 07:57, 11 March 2021 (UTC)
• Oppose moving to Function of several complex variables. "Several complex variables" long since became a common name for that whole field of study (it also goes by other names such as "complex analysis in several variables"). Witness how people write books and articles entitled Several Complex Variables, "What is Several Complex Variables?", etc., and how it gets treated as a singular noun. Also note how the Mathematics Subject Classification has, as a top-level heading, "Several complex variables and analytic spaces". The article, whose topic is not just the functions but the field of study, should remain called Several complex variables. Consistency with "Function of several real variables" may seem appealing superficially, but the two cases simply aren't analogous. Adumbrativus (talk) 09:16, 11 March 2021 (UTC)
  • "Several complex variables" is a classical name for the subject (and perhaps the most common), but so are the longer "Functions of several complex variables", "Theory of several complex variables", and "Theory of functions of several complex variables". It's true that "several complex variables" can denote a broader subject than just the function theory (i.e. analytic geometry), although the function theory is the core of the subject and the most classical meaning of the term. For example:
    • Several Complex Variables: "The present book grew out of introductory lectures on the theory of functions of several variables. Its intent is to make the reader familiar, by the discussion of examples and special cases, with the most important branches and methods of this theory"
    • Several Complex Variables and Complex Geometry, Part 3: Equates "several complex variables" with the "function theory of several complex variables"
    • Several Complex Variables II: Uses "several complex variables" interchangeably with "theory of functions of several complex variables"
    Perhaps "complex analysis in several variables" (it's unfortunate that this isn't even mentioned at complex analysis) would be a better article title though, for giving a precise and recognizable name for non-expert audiences. — MarkH₂₁^talk 16:33, 11 March 2021 (UTC)
• Oppose: basically per Adumbrativus. The term "several complex variables" seems to be quite well established. While "real analysis" can include the study of functions in several real variables, "complex analysis" is typically limited to functions in one complex variable. So, we need some term to refer to complex analysis in several variables. —- Taku (talk) 18:39, 11 March 2021 (UTC)

@Adumbrativus, MarkH21, TakuyaMurata, and Tazerenix: Thank you for your reply and follow up. What about Function theory of several complex variables? Function theory is the traditional name for complex analysis. But I'm a worried that the meaning of this name is too narrow.--SilverMatsu (talk) 15:30, 12 March 2021 (UTC)

Krantz, Steven G. (1992), Function Theory of Several Complex Variables (Second ed.), AMS Chelsea Publishing, p. 340, doi:10.1090/chel/340, ISBN 978-0-8218-2724-6

Noguchi, Junjiro (2016), Analytic Function Theory of Several Variables Elements of Oka’s Coherence, p. XVIII, 397, doi:10.1007/978-981-10-0291-5, ISBN 978-981-10-0289-2

Add two textbooks with the title Function theory.--SilverMatsu (talk) 16:38, 12 March 2021 (UTC)

Addendum:What I mentioned earlier is about complex analysis in several variables. So for now, I support Functions of several complx variables. Users searching for Several complex variables seem to be looking into what several complex variables mean, and Functions of several complex variables is the concise answer (IMO). It is true that this field is called several complex variables as a branch of complex analysis, but I'm not trying to change Category:Several complex variables.--SilverMatsu (talk) 01:29, 16 March 2021 (UTC)

Addendum2:Apparently, Krantz says to limit oneself to the study of one complex variable is to do complex analysis with one eye closed, so it seems too narrow to limit complex analysis to one variable. but, this does not seem to affect the redirect target. One complex variable seems to be a classical complex analysis.--SilverMatsu (talk) 15:32, 20 March 2021 (UTC)

amendment:How about turning Several complex variables into Several complex variables (DAB) pages instead of redirects?--SilverMatsu (talk) 15:25, 13 April 2021 (UTC)

Addendum:Article titles keep Several complex variables. Dab is added to clarify the proposal and is not intended to change the article name. (Assuming that the page name has been moved to Function of several complex variables.)--SilverMatsu (talk) 15:35, 15 April 2021 (UTC)

about the lead sentence

Currently, the lead sentence is In complex analysis, the theory of functions of several complex variables is the branch of mathematics dealing with complex-valued functions in the space $\mathbb {C} ^{n}$ of n-tuples of complex numbers, and especially the the theory of functions of several complex variables is the branch of mathematics part has not changed from the beginning. To be clear, the bold part was initially only the several complex variables. This was one of the reasons I support to functions of several complex variables as the article name, but if the article name doesn't change, it seems like the lead sentence needs to be improved a bit.--SilverMatsu (talk) 15:31, 3 April 2021 (UTC)

It seems to have improved now. Thanks to Michael Hardy.--SilverMatsu (talk) 15:08, 13 April 2021 (UTC)

It seems that the page has been moved

See Function of several complex variables. I'll ask if there was a consensus.--SilverMatsu (talk) 20:57, 22 April 2021 (UTC)

If there is no opposition, I will close it as moved.--SilverMatsu (talk) 15:24, 1 May 2021 (UTC)

The discussion above is closed. Please do not modify it. Subsequent comments should be made on the appropriate discussion page. No further edits should be made to this discussion.

Help requested with some references in the groups article

The article on groups is currently undergoing a featured article review, [here]. In the course of that, it was requested to add references for some statements. I have currently very little time and didn't find immediately one, can anyone help out here, please? thanks a lot (either include the references directly in the article and reply to the requests [here] or tell me and I can add them). Thanks a lot!

• "The word homomorphism derives from Greek ὁμός—the same and μορφή—structure."
• "These days, group theory is still a highly active mathematical branch, impacting many other fields." (we have a reference about the activity of this branch, but not about that it impacts many other fields)
• "A presentation of a group can also be used to construct the Cayley graph".

Jakob.scholbach (talk) 19:19, 2 May 2021 (UTC)

Jakob.scholbach Are homomorphic first references useful?--SilverMatsu (talk) 00:50, 3 May 2021 (UTC)

Yes, certainly. Jakob.scholbach (talk) 07:12, 3 May 2021 (UTC)

Jakob.scholbach, Allen Hatcher's Algebraic Topology has a heading Cayley Complexes in Section 1.3 with a good discussion. It assumes that you also have a list of the elements of the group, which I guess involves solving the word problem for groups. (So maybe the statement in the article should be tweaked.) Russ Woodroofe (talk) 08:08, 3 May 2021 (UTC)

Indeed, the Magnus, Karass, and Solitar source listed in the article says that the problem of computing the Cayley graph from the presentation is obviously equivalent to the word problem. I suggest removing the sentence, and possibly mentioning the Cayley graph elsewhere. Alternatively, restructure the paragraph to put Cayley graphs in the middle. I think the right thing to say is that "The elements and a set of generators of a group can be used to construct a Cayley graph, a device used to graphically describe discrete groups." Russ Woodroofe (talk) 09:30, 3 May 2021 (UTC)

• Wrt. applications of mathematics, the 2016 Nobel Prize in Physics was awarded for the discovery of what are now called topological materials [3] (to my surprise we don't seem to have an article on the whole class of such materials, but we do on the most important subclass, topological insulator). Actually investigating the chemical possibilities of these materials has involved substantial group theory, e.g., Topological Quantum Chemistry, Nature (2017), 547/7663:298-305. — Charles Stewart (talk) 05:28, 4 May 2021 (UTC)

x naught

Does the team agree that the correct way to read $x_{0}$ is "x naught" as claimed in this edit? Certes (talk) 23:54, 4 May 2021 (UTC)

I tend to agree with it. But I don't have any good sources. It's just what I picked up, who knows where. --Trovatore (talk) 00:20, 5 May 2021 (UTC)

I have reverted; it is an acceptable way to read the subscript 0, not "the correct" way; I find it deeply implausible that this could be supported by sources. --JBL (talk) 02:08, 5 May 2021 (UTC)

For what it's worth, I would probably pronounce it "x sub zero" or "x zero". To my ears "naught" sounds very British. —David Eppstein (talk) 02:23, 5 May 2021 (UTC)

x-naught is extremely British. Around here (Canada), it's x-zero. Headbomb {t · c · p · b} 04:20, 5 May 2021 (UTC)

Here in the US, I've heard "x naught", "x sub zero", and maybe "x zero". Bubba73 ^{You talkin' to me?} 04:59, 5 May 2021 (UTC)

I agree, naught is more British and nought is more American. --{{u|Mark viking}} {Talk} 05:36, 5 May 2021 (UTC)

Divided by a common language? I think it's just that British English spells two different concepts differently: naught means 'nothing' and is slightly archaic; nought means zero and in common use. As a British speller, the spelling x-naught jars with me; but either x-nought or x-zero seem quite natural (with their obvious pronunciations). NeilOnWiki (talk) 11:55, 5 May 2021 (UTC)

I also use British English and agree with Neil's analysis: nought means zero and naught (archaic) means nothing, but the two are interchangeable in loose chat. I say either "x zero" or something that sounds like "x naught". Having only written it with a 0 symbol, I never thought much about the spelling, but on reflection I think of it as "x nought". Certes (talk) 12:18, 5 May 2021 (UTC)

Thanks for all the useful input. The edit has been reverted, which seems the best course of action. I just noticed that Aleph number#Aleph-nought mentions aleph-nought, also aleph-zero or aleph-null so (if we can treat x as a placeholder for $\aleph$) I don't think we can say "x naught" is the correct way (my emphasis). Certes (talk) 12:18, 5 May 2021 (UTC)

That's the specific one that really bugs me, to be honest. As far as I'm concerned it's "aleph-naught", not "aleph-nought". --Trovatore (talk) 21:25, 5 May 2021 (UTC)

Only now do I realize the missed opportunity: I should have used the edit summary noughty noughty. --JBL (talk) 13:18, 5 May 2021 (UTC)

about Pseudoconvexity

Is it related to Convex analysis? It didn't seem to me to be related, but I wasn't studying enough so I thought I'd ask the community a question.--SilverMatsu (talk) 12:40, 11 May 2021 (UTC)

Convex analysis usually considers a situation in real Euclidean space while pseudoconvexity is considered in complex (Euclidean?) space $\mathbb {C} ^{n}$. So, no, I think. -- Taku (talk) 07:07, 12 May 2021 (UTC)

Thank you for your reply. So, maybe I think no too, so I'll try to get remove of the convex analysis.--SilverMatsu (talk) 08:41, 12 May 2021 (UTC)

By the way, I thought of a short explanation of the same article.

1. Convexity similar to holomorphically convex.
2. Convexity derived from the plurisubharmonic function.

Writing both is probably too long. thanks!--SilverMatsu (talk) 11:48, 12 May 2021 (UTC)

Would you think Numdam will meet Wikipedia:Notability (In English wikipedia) like Project Euclid?

It's my first time to add it to Wikipedia:Requested articles/Mathematics, so I thought I'd ask before adding it. I've added citations from there several times, but I don't have enough French ability to write the article (Numdam?) myself. (cf. fr:Numérisation de documents anciens mathématiques maybe… ) thanks!--SilverMatsu (talk) 05:50, 12 May 2021 (UTC)

The French article has nothing that looks like the kind of reliable in-depth independent sourcing needed to pass WP:GNG. Such sourcing would be needed for it to be notable. And since it is likely that sourcing (if it exists) would be in French, some ability to read French is probably also needed. —David Eppstein (talk) 06:11, 12 May 2021 (UTC)

Thank you for your reply. When I search for a paper written in French, I find Numdam, but I haven't found the source of Numdam itself yet.--SilverMatsu (talk) 07:16, 12 May 2021 (UTC)

@SilverMatsu: doi:10.1007/978-3-319-62075-6_6 seems a pretty good starting point. Headbomb {t · c · p · b} 12:20, 12 May 2021 (UTC)

Yes, certainly. Thank you! But I don't have any prior knowledge about Numdam so it takes time. --SilverMatsu (talk) 14:43, 12 May 2021 (UTC)

Proposal: Demystify math written in symbols by including programming language style code side-by-side

I'd be surprised if this doesn't come up, but it seems like the math articles are particularly low on value to readers not well versed in mathematical symbols. As a programmer I find these symbols looks impressive and cryptic, but rewritten in computer language style code can appear very trivial and unimpressive and hence easier to grasp, since computer language works with only a few rudimentary symbols instead of abstract levels of arbitrary symbols. All I'm saying is Wikipedia could be a great resource to teach math concepts if it did this I think, and programmers could benefit from being able to easily use math concepts in their work without deciphering them like hieroglyphics first --72.173.4.14 (talk) 10:54, 15 April 2021 (UTC)

There are several related problems, and the optimal solution must be a compromise between them.

A first problem is that many symbols should better replaced by prose. For example "for $x\in X$" is easier understood as "for x in X ". Copy editing articles for making such changes would solve a part of your concern. However many articles have other issues that are worse. So, I make such changes only as a side action of fixing other issues. I suspect that most of the competent math editors do the same. Your help would thus be welcome.

A second problem is that any "computer language style code" involves conventions that are programming language dependent. So for a wider understanding, it is better to keep the conventions that are established since centuries. Also many mathematical formulas are hardly expressible in a computer language style.

On the other hand, many articles could be improved by replacing a lengthy description of an algorithm by its description in pseudo-code, followed by a explanation of the meaning of the pseudo-code. Examples are Euclidean algorithm, where the very simple pseudocode appears only at the end of the article, and long division, where a pseudo-code description could provide a synthetic view that is difficult to extract from the given verbose description. D.Lazard (talk) 13:17, 15 April 2021 (UTC)

For the record I'm seeding the idea, it would be a colossal undertaking to even develop the style guidelines. I don't think the articles should be dumbed down, and this project should (would) be overseen by mathematicians. I'd say the existing notation has problems because it's usually just an image. This kind of concept could help with that by providing a version that can be selected (copy/paste). If I were asked how to format it, I would suggest putting a clickable icon beside appropriate math text that expands a box that cuts across the entire width of the container, so that any text before the math inline notation (including it) is above this box and any after is below it (after expansion) and inside this box just use something like calculator notation for traditional math, and programmer's notation for structured/stateful elements. This could be very useful because abstractions can be written as opaque functions and those can be links that when hovered over with the mouse reveal the body of the function at least up to one level. I just think this would add so much value to the many math articles that can seem impenetrable to non-mathematicians. Programming is something more and more people are familiar with and is generally easier to understand with less memorization and familiarization with symbols. For math that is not inline inside text it would be good to put the code in an already expanded box beside the math notation to put it on the same level, especially because often it's likely to be more readable to a layman --72.173.4.14 (talk) 15:01, 15 April 2021 (UTC)

Further note, a lot of this would probably be done by bots after some test pages are developed. It just seems like a commonsensical thing to do. Especially since the images that are currently generated are so unlike the rest of the text in Wikipedia --72.173.4.14 (talk) 15:05, 15 April 2021 (UTC)

RE "for x in X" I think this would be perfect to put in the "title" element in the HTML so it shows in a balloon when the mouse hovers over it. This will teach people the math symbols too if they do it enough times, which would be enriching. Edited: As for putting an icon to the side, it could be clicking anywhere on these static images also expands an info box just as such an icon would, just so it's less trouble to get your mouse over a small icon --72.173.4.14 (talk) 15:08, 15 April 2021 (UTC)

It's a nice idea, but there are many devils in the details. Much of math is not algorithmic, so you may be overestimating the fraction of math articles that could benefit. As a test case, you might think about how to implement your idea for the article Limit (mathematics). It's an extremely common topic that exists somewhere in the middle of the abstraction spectrum (not as concrete as arithmetic, but less abstract than much of the mathematics of the past couple centuries). Mgnbar (talk) 13:59, 17 April 2021 (UTC)

A good rule of thumb is to ask if a programmer without a degree in mathematics (who doesn't or can't memorize formulas, etc.) needs to implement the math in a program, then if that situation could arise, how would they do it. If it's a concept so trivial or abstract that it doesn't make sense in that context then it probably isn't a good candidate for a practical (non symbolic) translation to a less specialized language than that of a mathematician. The thing about programming languages is their syntax is usually minimal compared to mathematical syntax, preferring nested function names to introduction of hieroglyphics not found on keyboards --72.173.4.14 (talk) 00:46, 3 May 2021 (UTC)

• With respect to a style guide, that doesn't matter for your proposal yet. Style guides attempt to encourage consistency with what we have: the rules can only be made when the practice exists. — Charles Stewart (talk) 08:33, 22 April 2021 (UTC)

There has been some work done on making mathematical formulae self-explaining using information stored in Wikidata. For example, if you click on the formula $E=mc^{2}$ you will be connected to a query of Special:MathWikibase which gives an explanation in English. How this is done is partially explained in this paper. In October several of the equations in the article Matter wave were expanded to do this. StarryGrandma (talk) 06:08, 20 April 2021 (UTC)

Hmm. I have to say I'm skeptical that that's really a good idea. Clicking on equations is not an intuitive interface. It would be better to give a brief explanation in text, with links for further exploration. --Trovatore (talk) 02:17, 22 April 2021 (UTC)

+1 At least in the current the links don't yield any useful information, but at best repeating informations that usuallsy is already contained in the article using the formula. In addition there is visual marker clearly indicating that the formula represents a link.--Kmhkmh (talk) 16:05, 12 May 2021 (UTC)

Whatever anyone can take from this I think the current status quo of representing math with static (non-interactive) images is abysmal and should be an embarrassment to the math pages of Wikipedia. If that problem can't be solved automatically then at least this proposal could begin to supplement it. Honestly static images feels like the WWW of 20 years ago --72.173.4.14 (talk) 00:49, 3 May 2021 (UTC)

StarryGrandma, I'm not seeing it, maybe I'm looking in the wrong place. Can you specify an example equation? S Philbrick(Talk) 13:59, 12 May 2021 (UTC)

@Sphilbrick: Browse through the article's source and seek for <math qid=....> --CiaPan (talk) 14:26, 12 May 2021 (UTC)

The equation in StarryGrandma's post is an example. --JBL (talk) 14:37, 12 May 2021 (UTC)

Indeed. I didn't notice that until tested in Edge. --CiaPan (talk) 15:19, 12 May 2021 (UTC)

(ec) Also, the equation StarryGrandma placed above is linked, too. Alas, the link seems to not work in Samsung Internet browser in my phone nor in Google Chrome browser in my laptop. It does, however, in MS Edge. No idea how it behaves in other browsers. --CiaPan (talk) 14:38, 12 May 2021 (UTC)

It works fine for me on Edge (running on Windows) and on Firefox (running on a Mac). --JBL (talk) 17:42, 12 May 2021 (UTC)

Ugly duckling theorem

Could somebody please have a look at the dispute Talk:Ugly_duckling_theorem#Countable_set_of_objects_to_which_the_Ugly_duckling_theorem_applies and help to settle it? The controversy is whether the Ugly duckling theorem applies to a finite number n of objects or to a countably infinite number n. Many thanks in advance. - Jochen Burghardt (talk) 12:28, 27 April 2021 (UTC)

More precisely, the dispute is whether the Ugly duckling theorem applies to countable sets of $n$ objects or to some other sets of objects, such as sets of objects represented by ordinal numbers that do not commute under addition.Guswen (talk) 13:13, 27 April 2021 (UTC)

Thanks for helping with the capitalization, but this wasn't our problem. The dispute Talk:Ugly_duckling_theorem#Countable_set_of_objects_to_which_the_Ugly_duckling_theorem_applies is the one we need external help for. In my view, it boils down (per WP:RS) to the question whether the source Woodward.2009 does allow n in Ugly_duckling_theorem#Mathematical_formula to be countably infinite (as Guswen sees it) or not (as I see it; I summarized my view on Woodward.2009 in the last paragraph of Ugly_duckling_theorem#Discussion). - Jochen Burghardt (talk) 12:35, 12 May 2021 (UTC)

I was not able to make any sense of Guswen's arguments at all. --JBL (talk) 13:39, 12 May 2021 (UTC)

And what are your counterarguments? Guswen (talk) 13:55, 12 May 2021 (UTC)

More precisely, the dispute is whether the Ugly duckling theorem applies to countable sets of $n$ objects, i.e. whether the objects considered in the Ugly duckling theorem can be counted or not.

The meaning of the phrase "n things in the universe" is simply imprecise. Are these things countable? Or perhaps they are uncountable?

The grounds of our dispute are therefore broader that just WP:RS. Guswen (talk) 13:54, 12 May 2021 (UTC)

What do you think the definition of "countable" is? --JBL (talk) 13:55, 12 May 2021 (UTC)

You shall find my definition of a countable set in this Wikipedia article: countable set. Guswen (talk) 14:01, 12 May 2021 (UTC)

Please learn how to indent your posts properly. In the sentence "Suppose there are n things in the universe", what do you think the symbol n represents? (It may help you to read the introduction of the article when answering this question.) --JBL (talk) 14:03, 12 May 2021 (UTC)

I have no idea what does it represent. The meaning of the phrase "n things in the universe" is simply imprecise in my opinion. Would you please enlighten me? Guswen (talk) 14:07, 12 May 2021 (UTC)

I see your point. But the UDT does not apply to finitely many objects (Cf. Woodward.2009) Guswen (talk) 14:09, 12 May 2021 (UTC)

At present, the article is about a 50-year-old theorem concerning finite collections of objects. Woodward appears to introduce a new extension of that theorem, to countably infinite collections of objects. Maybe it is appropriate to have a section of the article Ugly duckling theorem that discusses this extension (I do not have an opinion on this). But what you have been doing is not that. The article talk-page would be a good place to discuss whether and how best to discuss the extension (again, something I do not have an opinion on). --JBL (talk) 14:19, 12 May 2021 (UTC)

The ugly duckling theorem was derived by Satosi Watanabe in 1969 in the publication "Knowing and Guessing: A Quantitative Study of Inference and Information". It is a part of a chapter "Logic and Probability" (begins at p. 299). In Section 7.3. of this chapter ("Formal Concept of Probability") on p. 336 he writes:

"We consider a set $X$ of objects $x$ (…). The number of $x$’s in $X$ may be finite, countably (enumerably) infinite, or continuously many.”

Then in Section 7.6 "Theorem of the Ugly Duckling" on p. 376 he proceeds to derive his theorem writing, among others:

"The purposes of this section is to show that from the formal point of view there exist no such thing as a class of similar objects in the world"

He provides an instructive comment also in p. 5 (my emphasis added):

"In the following we usually discuss the case in which $n$, the number of elements in a logical spectrum, is finite. Many of the results obtained will remain valid for the case in which $n$ is countably many (enumerably infinite), although they sometimes break down when $n$ becomes continuously many.”

This theorem is 52 years old, indeed. But his author derived it for enumerably (countably) infinite set of objects. This is not an extension of this theorem. This is the theorem itself.

If you want to derive your own similar theorem(s), within the ordinal numbers domain, for example, by all means please do.

But this article is about the original Satosi Watanabe ugly duckling theorem derived in 1969. Guswen (talk) 16:37, 12 May 2021 (UTC)

There is an existing article written at Ugly duckling theorem. If you read it, you will discover that its subject is, unquestionably, a theorem about finite collections. Maybe it would be appropriate for the article to, in addition or instead, discuss a theorem (of Watanabe or of Woodward or of someone else) about infinite collections. (I do not have an opinion about whether that would be good or not.) But, again, nothing you have done so far is related in any conceivable way to making that happen. The article talk-page is the correct place to discuss whether and how best to extend the article. --JBL (talk) 17:39, 12 May 2021 (UTC)

Precisely. There is the Ugly duckling theorem Wikipedia article, that is supposedly about the original Satosi Watanabe ugly duckling theorem derived in 1969. But the subject of this article, as you correctly mentions, erroneously states that it is a theorem about finite collections. It is not. Satosi Watanabe derived his own theorem in 1969 for enumerably (countably) infinite set of objects.

Therefore, this article requires appropriate correction to reflect the intentions, but more importantly derivations, of the author of this theorem. This Wikipedia article itself states that "It [the ugly duckling theorem] was derived by Satosi Watanabe in 1969."

Perhaps you would like to write your own Wikipedia article entitled "A version of the ugly duckling theorem for ordinal numbers", or similarly. But then (1) derive this extensional theorem, (2) peer-review it, (3) wait until the concept matures, and eventually (4) write this new Wikipedia article. I will keep my thumbs up for such an endeavor of yours.

For now, we're discussing the original Satosi Watanabe ugly duckling theorem that his own author derived for enumerably (countably) infinite set of objects. Your saying "of Watanabe or of Woodward or of someone else" is not only disrespectful to Satosi Watanabe. It also means that you do not understand this theorem.

Guswen (talk) 18:48, 12 May 2021 (UTC)

There is definitely a failure to understand happening in this conversation, but it's not at my end. --JBL (talk) 21:54, 12 May 2021 (UTC)

Let us then wait for a few days for some external feedback and then we will have to correct this article to reflect the author of this theorem (Satosi Watanabe) derivations. Guswen (talk) 21:59, 12 May 2021 (UTC)

Help with illustration needed

KC1

Is there anyone good with illustrations? I am currently brushing over determinant, and I'd like to include a few illustrations explaining the basic properties of the determinant of 2 x 2 matrices. We do have a few files along the lines I am thinking about in commons ([4]), such as the one here, but these also have a few shortcomings, and not everything I'd like to illustrate is there.

If anyone is good at illustrations and is willing to help out, please ping me and I will elaborate further. Thanks a lot. Jakob.scholbach (talk) 18:20, 12 May 2021 (UTC)

@Jakob.scholbach: You could add a request at Wikipedia:Graphics Lab/Illustration workshop. Certes (talk) 13:30, 13 May 2021 (UTC)

Behnke–Stein theorem (1939 or 1938) vs Behnke–Stein theorem (1948)

There seem to be two versions; the theorem on increasing sequences of domain of holomorphy and pseudoconvex domain (1939 or 1938), also the theorem claiming that the concatenated non-compact Riemann surface is a Stein manifold (1948).--SilverMatsu (talk) 14:17, 28 April 2021 (UTC)

So would you also add the 1948 theorem to Behnke–Stein theorem?--SilverMatsu (talk) 15:34, 1 May 2021 (UTC)

@SilverMatsu: If there are RSes that call the second theorem by the same name (as you say the Narasimhan paper does), then it's suitable to either create a section about the different theorem or a new standalone article entirely (assuming it's notable in the Wikipedia sense, e.g. WP:GNG). If there's not much to say, you can also just mention the other usage very briefly in the lead with a citation. — MarkH₂₁^talk 18:33, 13 May 2021 (UTC)

@MarkH21: Thank you for your reply. I create Draft:Behnke–Stein theorem (1948). I would also like to start the discussion of merging. I'm wondering whether to make the category complex analysis vs several complex variables.--SilverMatsu (talk) 05:12, 14 May 2021 (UTC)

Category:Several complex variables is a subcategory of Category:Complex analysis anyways, so the former should be fine. — MarkH₂₁^talk 05:49, 14 May 2021 (UTC)

Thank you for the advice. Yes, certainly.--SilverMatsu (talk) 11:13, 14 May 2021 (UTC)

References

• Behnke, H.; Stein, K. (1939). "Konvergente Folgen von Regularitätsbereichen und die Meromorphiekonvexität". Mathematische Annalen. 116: 204–216. doi:10.1007/BF01597355.
• Heinrich Behnke & Karl Stein (1948), "Entwicklung analytischer Funktionen auf Riemannschen Flächen", Mathematische Annalen, 120: 430–461, doi:10.1007/BF01447838, S2CID 122535410, Zbl 0038.23502
• Raghavan, Narasimhan (1960). "Imbedding of Holomorphically Complete Complex Spaces". American Journal of Mathematics. 82 (4): 917–934. doi:10.2307/2372949. This reference also reads the 1948 theorem as Behnke–Stein theorem.

Wikipedia:Articles for deletion/Titanic prime and the large prime number article proposal

A recently concluded AfD, Wikipedia:Articles for deletion/Gigantic prime, was closed as 'redirect to megaprime', and following the general sentiment there I began a related AfD, Wikipedia:Articles for deletion/Titanic prime. In it, D.Lazard has proposed that we merge all treatments of ranges of large prime numbers with the current treatment of largest prime number into a comprehensive article, the not-yet-extant large prime number.

I've created a topic on an article talk page for more specific discussion about what to do with these pages at Talk:Largest known prime number#Wikipedia:Articles for deletion/Titanic prime and the large prime number article proposal. Since this affects a fair few maths articles, SilverMatsu pointed out that it would be good to advertise this discussion here. The search for large primes is one of the more media-friendly parts of maths, so this could be an effort with more than usually observable impact for us. — Charles Stewart (talk) 01:38, 15 May 2021 (UTC)

Median of a gamma distribution

I've been involved in a rather one-sided discussion (that is, with almost nobody but me) at Talk:Gamma distribution#Median of the gamma distribution for about 2 years now. I could use a second and third opinion. My contribution to the problem was to do some original research and get it peer reviewed and published. Maybe someone will say yes or no to us using it in the article now. (Please excuse the cross-posting with WikiProject Statistics.) Dicklyon (talk) 22:47, 15 May 2021 (UTC)

Actually, an editor already added a paragraph to the article about it, before I posted there. More eyes are still welcome. Dicklyon (talk) 22:53, 15 May 2021 (UTC)

It wouldn't be the only journal paper written and published for the main purpose of providing a source to add a claim to Wikipedia. Thanks for taking such efforts to improve the article. —David Eppstein (talk) 22:59, 15 May 2021 (UTC)

Agreed! --JBL (talk) 02:29, 16 May 2021 (UTC)

about Blackboard bold

Before we talked about blackboard bold in the style manual, but the blackboard bold article still seems to explain not to use blackboard bold except on the blackboard. Do we improve the article?--SilverMatsu (talk) 15:49, 15 May 2021 (UTC)

the blackboard bold article still seems to explain not to use blackboard bold except on the blackboard The article Blackboard bold is not an instruction manual, and it also does not say what you've said. You should of course feel free to improve any article on Wikipedia; for the particular article Blackboard bold, the best way to improve it would be to find reliable sources that discuss it (rather than, as is currently the case, a bunch of primary sourced claims that various individual books or authors happened to use or not use it in various contexts). --JBL (talk) 15:57, 15 May 2021 (UTC)

Thank you for the advice and article improvements. Certainly the article doesn't seem to say what I pointed out. But the article will be improved because you tagged it properly.--SilverMatsu (talk) 08:41, 16 May 2021 (UTC)

Help needed for an edit war

There is an edit war in which I am implied at Flat module. Help would be welcome. D.Lazard (talk) 07:21, 9 May 2021 (UTC)

This isn't an edit war. You are blindly removing new material off this page and refusing to let any improvements in. Taking a few minor complaints about a few (small) points does not warrant a blank removal of material. If you want a citation, try asking if the author knows of one, or try to dig one up yourself. Furthermore, if something could be restated in a more conformant way of wikipedia standards, make that edit. Those are some more constructive avenues for handling disagreements over material. Kaptain-k-theory (talk) 16:42, 10 May 2021 (UTC)

It is definitely an edit war, and both of you should stop. Meanwhile, it is extremely unhelpful to personalize disputes, as you have done at Talk:Flat module; please try to focus on content, not on other contributors. --JBL (talk) 18:22, 10 May 2021 (UTC)

I hope that a resolution has been found by now :) — MarkH₂₁^talk 17:32, 18 May 2021 (UTC)

Links to disambiguation pages

Hi. There are a few mathematics-related disambiguation pages that have attracted some links that need fixing: total relation (18 links), boundedness (10 links), and minimal prime (3 links). Is there a mathematician who feels like tackling some of these? Thanks in advance! Lennart97 (talk) 10:45, 12 May 2021 (UTC)

I've fixed the last one (all Minimal prime (recreational mathematics)) but will leave the others to an expert. Certes (talk) 10:58, 12 May 2021 (UTC)

I've mostly done bounded. If someone else could take a look at Hilbert–Pólya conjecture (should that be unbounded function, bounded operator, unbounded operator?) and Tail sequence (should this unsourced definition-only orphan be merged somewhere?) that would be great. --JBL (talk) 23:24, 12 May 2021 (UTC)

For Hilbert–Pólya conjecture, the hypothetical operator would be a linear operator that is not a bounded operator. However, note that the cited reference does not mention boundedness anyways, and there aren't many good references for this since it's hypothetical and seems to be mostly of more tangential interest to physicists and receives little more than speculative interest in number theory. I'm not sure why unbounded operator specifically restricts to operators of subspaces of a given space since that is not always the convention in all areas of mathematics. — MarkH₂₁^talk 23:42, 12 May 2021 (UTC)

Would it be appropriate to merge somewhere? BD2412 T 02:56, 13 May 2021 (UTC)

@BD2412: If you mean Hilbert–Pólya conjecture, it's still notable (GNG-wise) and separate enough from Riemann Hypothesis to have a standalone article. If you were referring to JBL's question about Tail sequence then I don't know! — MarkH₂₁^talk 13:46, 13 May 2021 (UTC)

Maybe BD2412's comment was about Unbounded operator? But also Trovatore do you have any thoughts about what should be done with Tail sequence? --JBL (talk) 14:09, 13 May 2021 (UTC)

I was responding to [User:MarkH21|MarkH21]]'s comment that "there aren't many good references for this since it's hypothetical and seems to be mostly of more tangential interest to physicists and receives little more than speculative interest in number theory". I believe that was in reference to Hilbert–Pólya conjecture. However, I'm always for a good merge for any of these topics that may be better suited for explanation in the context of a broader topic. BD2412 T 16:02, 13 May 2021 (UTC)

As regards tail sequence — as far as I can work out, it's saying something pretty trivial (basically the complement of an initial segment of a limit ordinal) in a complicated and indirect way, bringing in "normal functions" only to not really use them. Doesn't seem to be used anywhere, and I don't recall running across it as a term of art (it's plausible as a nonce term, but I would expect the author to give at least a brief gloss). If the page creator has an attestation, it might rate a line in glossary of set theory if there is such a page; otherwise I'd say delete. --Trovatore (talk) 17:39, 13 May 2021 (UTC)

Prodded and notified. --Trovatore (talk) 18:21, 13 May 2021 (UTC)

• I think you might not have parsed the definition correctly: if we call your class of sequences coinitial sequences, my interpretation is that tail sequences are subsets of coinitial sequences that are cofinal in those sequences. That the definition is unclear enough that I'm not altogether sure which interpretation is right only provides further support for your PROD. — Charles Stewart (talk) 09:00, 14 May 2021 (UTC)

  Hmm, let's go ahead and reproduce the short definition here in case it gets deleted:

  In mathematics, specifically set theory, a tail sequence is an unbounded sequence of contiguous ordinals. Formally, let β be a limit ordinal. Then a γ-sequence $s\equiv \langle s_{\alpha }|\alpha <\gamma \rangle$ is a tail sequence in β if there exists an ε < β such that s is a normal sequence assuming all values in $\beta \setminus \epsilon .$

  Following the pipe from "normal sequence" to normal function, we read that it's a continuous, strictly increasing map. Putting all these things together (and we don't even need "continuous"), the only possible way to satisfy these requirements is if $\gamma =\beta -\epsilon$ and $s\,\!$ is the obvious $s_{\alpha }=\epsilon +\alpha$. That's why I said it was "bringing in normal functions only to not really use them".

  Not, as you say, that it really matters for the purposes of this discussion. --Trovatore (talk) 16:34, 14 May 2021 (UTC)

  Hmm, for completeness, I should agree that there is a small ambiguity. I was implicitly reading "assuming all values in β\ε to mean all and only values in β\ε. You could read it instead to mean that it also assumes some values below ε. But in that case there is a smallest (only) α such that s_α = ε, and from that point on, it's just the complement of an initial segment. --Trovatore (talk) 17:54, 18 May 2021 (UTC)

Proposal: Template:infobox theorem

Main page: Template:infobox theorem

I would like to propose a standardized template for mathematical propositions and results (theorems, conjectures, axioms, lemmas, etc.). It should contain, in the very least, the following:

• Author
• Year authored
• Lay statement
• Precise statement
• Illustration
• Fields affected / concerned
• Reference number (in some suitable index)

We can take cues from existing templates before submitting to WP:RT. What do you think? — Preceding unsigned comment added by François Robere (talk • contribs) 17:26, 16 May 2021 (UTC)

I think infoboxes work well for things that can be adequately described by database entries (stars, for example) and very badly for things that require nuance and reasoned description rather than filling in boxes. I think theorems fall more on the "requires detailed textual description rather than filling in boxes" side of that dichotomy. I think adding infoboxes would put great emphasis on the wrong aspects of the topic (such as who proved it and when) rather than emphasizing the important aspects (the mathematics that the theorem is about), and even for the aspects they emphasize are likely to oversimplify (most important theorems have a long history of refinement and rediscovery rather than a single prover and date). See WP:DISINFOBOX and particularly the description there of bad infoboxes as "an oversimplified mass of disconnected facts devoid of context and nuance". —David Eppstein (talk) 19:26, 16 May 2021 (UTC)

@David Eppstein: Do you have any views on {{Infobox SCOTUS case}}? Certainly nuance is involved there. Michael Hardy (talk) 17:47, 17 May 2021 (UTC)

Judging from the first of the "links here" pages, Marbury v. Madison: The first two lines of text of the actual article tell me the important stuff about what kind of thing the topic is (a US Supreme Court case) and what point of law it established. The infobox, on the other hand, is purely decorative for the equivalent of six lines of text, followed by purely technical information that is essentially completely uninformative to me. It is not the sort of thing that should be taking up so much screen real estate in the article and distracting attention away from the important information. It is at best a waste of space, when it is not actively taking away value from the article by distracting readers from the actual information. So although I have no expertise or interest in editing law case articles, I think that WP:DISINFOBOX is very relevant there as well. —David Eppstein (talk) 18:25, 17 May 2021 (UTC)

@François Robere: This already exists, at {{Infobox mathematical statement}}. — MarkH₂₁^talk 19:10, 17 May 2021 (UTC)

@MarkH21: Thanks! How did I miss that? :-P François Robere (talk) 19:53, 17 May 2021 (UTC)

The existing template has a single "statement" field; would it be better to add an optional field for precise notation? François Robere (talk) 10:40, 18 May 2021 (UTC)

@François Robere: What do you mean? What would the optional field be called and what is it for? — MarkH₂₁^talk 17:20, 18 May 2021 (UTC)

@MarkH21: The way I understand it at the moment, there are three ways for describing eg. a conjecture: rough verbal description (in "lay terms"), precise verbal statement, and precise symbolic statement. For example, for the first of the Weil conjectures we could state imprecisely that "ζ(X, s) is a rational function of T = q^−s"; and more precisely that "ζ(X, s)=$\prod _{i=0}^{2n}P_{i}(q^{-s})^{(-1)^{i+1}}={\frac {P_{1}(T)\dotsb P_{2n-1}(T)}{P_{0}(T)\dotsb P_{2n}(T)}}$" (or something of the sort). François Robere (talk) 17:40, 18 May 2021 (UTC)

I've seen the changes. Thanks! François Robere (talk) 18:14, 18 May 2021 (UTC)

I personally like an idea of infobox in general and not just for non-math articles. A common complaint on math articles is that they look like they are written and are aimed at math people not the general public. At least an infobox can be helpful in addressing this issue. Mathematically, when a theorem is proved or who proved it might be *irrelevant* but non-mathematically some readers might find such info interesting. I suggest the infobox have a column "related theorems"; that would be good for navigation. E.g., the Hahn--Banach theorem infobox can have the hyperplane separation theorem as a related theorem. -- Taku (talk) 01:41, 20 May 2021 (UTC)

about Template:PlanetMath

Apparently, id seems to be obsolete and should be replaced with title name, the Canonical name should remove the space from the title name. Would anyone edit it directly or create a bot? thanks!--SilverMatsu (talk) 06:40, 28 May 2021 (UTC)

It's not obvious that this can be done automatically or by a simple textual substitution as you suggest without creating even more errors. The most recent discussion in 2019 suggested that there were few enough of these that it would be better to handle them one at a time by hand: https://en.wikipedia.org/wiki/Wikipedia_talk:WikiProject_Mathematics/Archive/2019/Feb#RIP_PlanetMath%3F —David Eppstein (talk) 07:35, 28 May 2021 (UTC)

Thank you for teaching me.--SilverMatsu (talk) 08:22, 28 May 2021 (UTC)

Assessment of Transfinite number

The priority of the article Transfinite number was last assessed in 2008, when it was lowered from High to Low. Its class was changed from Stub to Start in 2018. I think that the low priority assessment was at least partly based on the poor quality. The quality still leaves room for improvement, but shouldn't its priority be higher? Based on my feeling that the subject is "a must-have for a print encyclopedia", combined with the criteria of Wikipedia:Version 1.0 Editorial Team/Release Version Criteria § WikiProject priority assessments, I wonder if its importance should in fact not be rated as  Top . (I have more problems applying this WikiProject's own priority rating scheme, as I think the criteria as presented there cannot be applied to a subject in isolation, but only to an article as a node contextualized in an everchanging web, and seem to be more coupled to an article's quality than is desirable for a supposedly independent parameter.)  --Lambiam 08:29, 23 May 2021 (UTC)

Definitely not top. That is for things that every educated person (not just every mathematician) should know about. Might be medium rather than low, I'm not sure. Importance ratings are not very important, though. —David Eppstein (talk) 16:46, 23 May 2021 (UTC)

I would rate it as High priority, not Top. Low seems very wrong; I agree that there's often a bias against articles with currently low quality. - CRGreathouse (t | c) 02:34, 24 May 2021 (UTC)

I agree with high; not top. Bubba73 ^{You talkin' to me?} 02:49, 24 May 2021 (UTC)

 OK, I've restored it to  High . Not letting an article's low quality bias its priority assessment seems important to me; large discrepancies between high priority and low quality can be used to flag articles that need attention.  --Lambiam 09:56, 24 May 2021 (UTC)

You are aware the Transfinite number is merely a disambiguation page that links to Ordinal number and Cardinal number, aren't you? The latter articles are the "must-have(s) for a print encyclopedia". - Jochen Burghardt (talk) 10:48, 24 May 2021 (UTC)

Hmm, maybe it should be such a disambiguation page, but it isn't, currently, at least not literally. There's a wrinkle here; some writers seem to use "transfinite" to mean any non-Dedekind finite set, in a non-axiom-of-choice context. In my opinion this is ahistorical, but it is a usage that exists, and in covering it the page seems to have become to some extent about the term "transfinite" (generally undesirable but possibly hard to work around in this case).

If the page is destined to continue to be about the term, then I sort of agree it's low-ish priority, medium at best. If we were to turn it into a legit disambig page, I think those are not even eligible for priority rankings. --Trovatore (talk) 02:30, 26 May 2021 (UTC)

I might add that there's a third possibility. As I understand it (and I have no good sources for this) Cantor used the term "transfinite" as a sort of middle ground between the finite and what he saw as the truly infinite. His transfinita ordinata were beyond a bound (that is, greater than a limit ordinal), but none of them was without bound. This is a very interesting and subtle idea, closely connected for Cantor with his ideas about God, who is truly infinite, unlike the mere transfinite numbers. If we (found sources and) rewrote the article to be specifically about that idea, I would love to see that listed as mid-priority. --Trovatore (talk) 04:48, 26 May 2021 (UTC)

I've added ratings to hundreds if not thousands of math articles. That one strikes me as "low", or "mid" at most. (It's currently marked "high") Why? It is providing a a definition for a historical term that has kind of fallen by the wayside. The definition is not particularly complex or important. "High" is usually something reserved for something important that school students would study or need to know. This is not that. I agree with Trovatore that if it had more history-of-math to it, it would be mid.

BTW, @XOR'easter: removed a section called "wolfram spam", but the removed material predates wolfram by at least 5 decades. It is covered in J.H. Conways book On Numbers and Games but I'm fairly certain it predates Conway, as he seems to be recaptulating known results. However, I'm not restoring that content, because I don't think it belongs in this article anyway. (I don't know where it belongs). 67.198.37.16 (talk) 23:14, 26 May 2021 (UTC)

That removal was part of a massive cleanup of material added to many articles by Wolfram employees in order to boost the visibility of A New Kind of Science and Wolfram more generally. A not-insignificant fraction of the material they added was badly written and/or poorly sourced content on textbook topics. XOR'easter (talk) 23:34, 26 May 2021 (UTC)

Conway certainly gave lectures on the topic in the early 1980s (in which he wrote out $\omega ^{\omega ^{\omega ^{...}}}$ then rotated the blackboard to display $\varepsilon _{\varepsilon _{\varepsilon _{...}}}$). Certes (talk) 23:42, 26 May 2021 (UTC)

OK Thanks. I restored the section and credited Conway. I'm starting to suspect that its actually due to Cantor, but can't quickly research that. I expanded On Numbers and Games slightly; all the details are in surreal numbers. 67.198.37.16 (talk) 01:55, 27 May 2021 (UTC)

Incidentally, @XOR'easter and Blablubbs: I've just discovered that there's more Wolfspam around, related to his book "Idea Makers". I just nuked one at Richard Feynman (added by OrdinaryArtery), but there's also this at Richard Crandall; presumably it's been spammed onto articles of people not named Richard, as well. --JBL (talk) 02:06, 27 May 2021 (UTC)

Just the four I think. Certes (talk) 10:38, 27 May 2021 (UTC)

Thanks, Certes. I cleaned up Crandall. The paragraph in Ada Lovelace sounds like it was written by one of the socks but was in fact added by Kaldari, and the reference in List of Jewish mathematicians, which is not accompanied by any promotional text, was added by Kyuko. The mention at Stephen Wolfram is appropriate. --JBL (talk) 12:18, 28 May 2021 (UTC)

OMG. Selecting a random link from User contributions for Spikeylegs shows spam on Combinatory logic. I find this highly objectionable. Cleaning up this particular instance now. I now imagine there's a lot of them.

Huh. I looked at the other SpikeyLegs contributions and it looks like more or less all of them have been reverted. I must have gotten lucky finding the one that was not.67.198.37.16 (talk) 02:17, 29 May 2021 (UTC)

Check out User:Blablubbs/Wolfram (this is the same link XOR'easter gave above) -- we got most of it, but there are probably bits and pieces that got missed. --JBL (talk) 02:41, 29 May 2021 (UTC)

FAR notice

I have nominated Laplace–Runge–Lenz vector for a featured article review here. Please join the discussion on whether this article meets featured article criteria. Articles are typically reviewed for two weeks. If substantial concerns are not addressed during the review period, the article will be moved to the Featured Article Removal Candidates list for a further period, where editors may declare "Keep" or "Delist" the article's featured status. The instructions for the review process are here. Extraordinary Writ (talk) 21:06, 29 May 2021 (UTC)

Please do help in improving the Laplace–Runge–Lenz vector, particularly by adding citations to reliable modern sources, clarifying confusing passages, or simply by adding your comments to its featured article review. Thank you very much! :) Willow (talk) 09:42, 31 May 2021 (UTC)

Jun 2021

Proposal: change terminology from "recursive" to "computable"

In many articles concerning the mathematical field of computability theory, I propose changing the terminology from "recursive X" to "computable X". For example:

"recursion theory" ⇒ "computability (theory)"

"recursive function" ⇒ "computable function"

"recursively enumerable", "r.e." ⇒ "computably enumerable", "c.e."

I have two reasons for this proposal:

1. "Recursion theory" was the original name for computability, and the most common name throughout the 20th century. However, in the last 20 years (?), there has been a sea change towards the terminology "computable". Essentially all papers and books written recently about recursion/computability theory use the term "computable" in favour of "recursive". Sadly, ngrams aren't supporting this, but I think this is for the reasons I outline below - the term "recursion" is used in a much broader sense. However, if you look at recently published computability articles on zbMATH, you will notice they all use "computable" instead of "recursive". Further evidence is Soare's 2016 book "Turing Computability", which is essentially a second edition of his 1987 book "Recursively Enumerable Sets and Degrees", with most instances of the word "recursive" replaced by "computable".
2. The word "recursive" is ambiguous, as it can refer to many other things, particularly the more general notion of recursion. In general, the usual (informal) meaning of "recursive" doesn't coincide with the computability-theoretic meaning. Indeed, this was the primary motivation behind the change described in the previous item.

There are plenty of pages which use the outdated terminology, such as recursively enumerable set, recursive ordinal, forcing (recursion theory) and index set (recursion theory). I would rename these to computably enumerable set, computable ordinal, forcing (computability) and index set (computability) respectively.

Note: I am not proposing this change for every instance of the word "recursive". For instance, I would keep primitive recursive and Kleene's recursion theorem as they are, as those are still the popular names for those concepts.

--Jordan Mitchell Barrett (talk) 05:30, 21 April 2021 (UTC)

@Jordan Mitchell Barrett: To clarify and reiterate, you're not proposing article moves for those three examples, right? So not replacing the disambiguation Recursive function with Computable function, but rather just a terminology change solely within the prose of articles within computability theory? — MarkH₂₁^talk 07:30, 21 April 2021 (UTC)

@MarkH21: I am proposing a terminology change, which might affect the titles of some articles. However, this change is limited in scope to articles about the mathematical field of computability theory. Regarding the three examples I gave at the start:

• Recursion theory already redirects to computability theory, so there would be no title changes here.
• Recursive function is a disambiguation page about the more general, informal notion of "recursive", therefore this is out of the scope of what I'm proposing. Hence no changes here. If there was an article called recursive function (recursion theory), I would be proposing to move it to computable function. However, this is not the case.
• I am proposing to move recursively enumerable set to computably enumerable set.

--Jordan Mitchell Barrett (talk) 08:18, 21 April 2021 (UTC)

• Oppose The two first proposed changes are almost already done, and completing them does not require any discussion here; the third one is against Wikipedia general policy. In details, Recursion theory is already a redirect to Computability theory. So, I agree with changing the disambiguating parentheses in article titles from "(recursion theory)" to "(computability theory)". Recursive function is a disambiguation page linking to several meanings; the one that is related to computability theory is General recursive function, which is one of several models of computation for computable functions. "Recursive function" was also presented as an other name for "computable function" before saying that "mu-recursive functions" are a model of computation for computable functions. I have just fixed this. The term recursively enumerable is well established and unambiguous. It is not the role of Wikipedia to change an established term, so I strongly oppose to any change of recursively enumerable. D.Lazard (talk) 09:21, 21 April 2021 (UTC)

"Recursively enumerable" or "r.e." is an outdated term, and "computably enumerable" or "c.e." is used instead in modern literature on computability theory (last 20-30 years). You are correct that the term "recursively enumerable" is unambiguous, and established in the sense that older literature uses it. To clarify, I would keep "r.e." as a synonym in the lead, but change all subsequent occurrences and move the article to computably enumerable. --Jordan Mitchell Barrett (talk) 09:45, 21 April 2021 (UTC)

You must provide sources attesting that "recursively enumerable" is an outdated term. A source using "computably enumerable" witout discussing the use of these terms is not such a requested source. Without such sources, your assertion that the term is outdated is WP:original research. In any case, Wikipedia is not aimed for specialists of computability theory, and must not be confusing for non-specialists. The systematic change that you propose would be highly confusing for people who use results of computability theory without being specialists of it (for example, the existence of a recursively enumerable set that is not recursive is widely used in algebra and number theory for proving that some properties are not decidable; an important example is Fröhlich–Shepherson theorem of non-computability of polynomial factorization over some explicit computable fields). D.Lazard (talk) 10:42, 21 April 2021 (UTC)

@D.Lazard: naturally, it's hard to find sources attesting to this, but here is what I could find in a quick search:

Soare's 1996 essay "Computability and Recursion" was the original proposal to those in the field to change terminology from "recursive" to "computable". He wrote an revised version in 1999, called "The History and Concept of Computability", in which he remarks (sec. 7):

Researchers in the subject have recently changed the the name of the subject from “Recursion Theory” to “Computability Theory” in order to make clear this distinction [in meaning between the terms]. Thus, the term “recursive” no longer carries the additional meaning of “computable” or “decidable,” as it once did. This reinforces the original meaning of “recursive” and induction as understood by Dedekind, Peano, Hilbert, Skolem, Godel ... and by most modern computer scientists, mathematicians, and physical scientists. Presently, if functions are defined, or sets are enumerated, or relative computability is defined using Turing machines, register machines, or variants of these ... then the name “computable” rather than “recursive” will be attached to the result, ... Thus, the terms “recursive” and “computable” have reacquired their traditional and original meanings, and those understood by most outsiders.

Soare, in his book "Turing Computability", also discusses the change briefly (sec. 17.7.2):

After the articles [Soare 1996] and [Soare 1999] on the history and scientific reasons for why we should use “computable” and not “recursive” to mean “calculable,” many authors changed terminology to have “recursive” mean only inductive and they introduced new terms such as “computably enumerable (c.e.)” to replace “recursively enumerable.” This helped lead to an increased awareness of the relationship of Turing computability to other areas. There sprang up organizations like Computability in Europe (CiE) which developed these relationships.

Cooper and Odifreddi also mention the change in "Incomputability and Nature":

Things started to change in earnest around 1995–96. These changes were rooted in two seemingly unrelated developments, one philosophical and political in content, and the other technical. The first involved a deliberate attempt to reinstate Turing’s terminology in keeping with the subject’s origins in real world questions — ‘computable’ in place of ‘recursive’ etc. — a project outlined in Robert Soare’s 1996 paper on ‘Computability and recursion’.

I disagree that this change would be confusing - in fact, I think it would clarify things, as "computable", rather than "recursive", is now the popular and accepted term for the concept, both for specialists in computability, and people who know not the subject. The one exception might be older mathematicians with weak connections to computability theory, who may not be aware of the terminology change (e.g. algebraists). However, your result could equally well be stated "there is a computably enumerable set which is not computable", and I think the meaning of this is clearer. --Jordan Mitchell Barrett (talk) 20:51, 21 April 2021 (UTC)

• Strong support. It is my understanding that this is the usage in the field these days. While D.Lazard is completely correct that it is not Wikipedia's role to change usage, that is not what has happened here — usage has changed in the wild. Unfortunately User:CBM seems to have stopped editing; he would be the one I would naturally go to to find good sources.
  As a side note, the content of general recursive function at the moment is largely about one particular model of computation, which could be called μ-recursion. That content should appear under some such title as μ-recursion, and general recursive function should be a redirect to computable function, which should be slightly rewritten to clarify that it is about the precise concept with many different provably equivalent definitions, and not about informal computability. See my remarks in talk:general recursive function. --Trovatore (talk) 18:31, 21 April 2021 (UTC)
• Comment. I just polled some theoretical-CS faculty colleagues on this; they were not aware of a shift in terminology, and tend to use older textbooks (Sipser and/or Lewis and Papadimitriou) where recent trends might not be apparent. But we all agreed that "computable" is an acceptable and familiar alternative to "recursive", and probably preferable because of the potential of confusing "recursive" with the programming-language concept of recursion. —David Eppstein (talk) 19:43, 21 April 2021 (UTC)

Yes, (older) people who know some computability, but are not specialists, may not be aware of this change. The TCSists I know like the term "decidable", e.g. for type-checking, and to be clear, I would keep such terms as synonyms in the articles. However, I agree that "computable" is clearer than "recursive" to almost everyone. --Jordan Mitchell Barrett (talk) 20:54, 21 April 2021 (UTC)

They were not all older, but "know (and teach) some computability, but are not specialists" is accurate. On the other hand, I think that because the rudiments of this material are commonly taught in undergraduate computer science programs, making the main articles on this material accessible to students at that level is important, per WP:TECHNICAL, and that the nomenclature they learn it by is at least as relevant as current specialist practice in making this decision. Fortunately, this doesn't lead to much conflict: from that point of view, moving away from "recursive" also comes out as a good idea. —David Eppstein (talk) 01:00, 22 April 2021 (UTC)

• Side note I was actually not a fan of Soare's change at the time he initially proposed it, in the mid-nineties, for a couple reasons. One, I'm generally skeptical of self-conscious programs of language reform. Beyond that, I was concerned that it seemed to be trying to make Church's thesis true by fiat, because I thought of it as "all computable functions are recursive". It was explained to me that that wasn't the point; that Soare simply wanted to repurpose "computable" as the precise technical term for what had been called "recursive", so that now Church's thesis (or if you prefer the Church–Turing thesis, but I did go to UCLA after all) would be something like "all informally computable functions are computable".
  If I could wave a magic wand and undo the change, would I? Probably not. I've gotten used to it by now. I'm still not a big fan of the "political" subtext of Cooper's paper, linked above, but the terminology does have some practical advantages, in that it decouples the concept from self-reference, whereas on its face "recursive" looks like it's about self-reference.
  In any case, if we did decide to go with the older terminology, then most of the content currently at computable function should be moved to general recursive function or whatever name we picked, and that article should not be so tightly tied to μ-recursion. I don't think that's a very good plan, but it's the only reasonable alternative to the proposed changeover. --Trovatore (talk) 23:02, 21 April 2021 (UTC)

Update: it seems there was consensus around some things, such as changing disambiguating parentheses in article titles from "(recursion theory)" to "(computability)". Hence, I've now moved Forcing (recursion theory) to Forcing (computability), and Index set (recursion theory) to Index set (computability). I tried to move Reduction (recursion theory) to Reduction (computability), but the latter is already a redirect to Reduction (complexity). In any case, it looks like Reduction (recursion theory) should be merged into Reduction (complexity), which I've proposed.

I'd still like to move the following articles:

• Recursive ordinal ⇒ Computable ordinal
• Recursive set ⇒ Computable set
• Recursively enumerable set ⇒ Computably enumerable
• Recursively inseparable sets ⇒ Computably inseparable

My reasons are as stated above. My interpretation of the above discussion is that I have support from Trovatore and David Eppstein, with some disagreement from D.Lazard (who still hasn't responded after I provided sources witnessing the change in terminology). I would appreciate input from other editors on whether they support or oppose such changes.

For now, I don't think we should move Recursive language, as this concept seems more in the realm of theoretical CS, where they may use different terminology. Then again, maybe Decidable language is a more common name? --Jordan Mitchell Barrett (talk) 01:23, 26 April 2021 (UTC)

• "Recursive language" appears more frequent than "decidable language" in recent publications although both are in similarly-wide use. However, a lot of the Google Scholar hits for "recursive language" appear to be in the context of the development of natural languages, as a way of distinguishing basic utterances from things with a nontrivial syntax, far from the technical meaning used here. "Decidable language" would be more unambiguous. I don't think this has been a very active area of computer science research for the last 50 years; it's more just a basic concept that is occasionally used as a tool in other research topics. So for instance in relativized computational complexity theory (itself not exactly a hot area) one still sees "recursive oracle" rather than "decidable oracle". —David Eppstein (talk) 01:39, 26 April 2021 (UTC)
• I have not responded before because I had nothing to add to my comment. Presently, I acknowledge that sources have been provided that support the terminology shift. Also, it is better that terminology gives hints to the meaning of the used terms and phrases. This is the positive aspect of this terminilogy shift. So, I do not oppose anymore to the four remaining proposed moves, if a note is added to the moved articles for explaining the terminology shift (a single sentence with a reference to Soares may suffices). D.Lazard (talk) 09:45, 26 April 2021 (UTC)

Great! I will absolutely reference the old terminology and explain the shift in those articles. --Jordan Mitchell Barrett (talk) 22:38, 26 April 2021 (UTC)

Looking for redirects "r.e." and/or "c.e." (both are important, since they are hard to find by string search), I found the link RE (complexity). Should it be renamed to CE (complexity)? There is also R (complexity); more "R"s might be found in similar classes. - Jochen Burghardt (talk) 07:25, 27 April 2021 (UTC)

We shouldn't be making up new names for complexity classes — they're a piece of standardized notation, not merely an abbreviation for an English phrase. You wouldn't propose changing $\mathbb {Z}$ to $\mathbb {I}$ merely because we're mostly writing in English rather than German these days; this comes across as the same sort of suggestion. I don't know of any sources that call these ones anything other than R and RE. That's how they're listed in the Complexity Zoo [5], without any mention of synonyms, for instance. —David Eppstein (talk) 07:38, 27 April 2021 (UTC)

• Support. I agree with Trovatore that, for better or worse, the terminology used by practicing logicians has changed, so it makes sense for Wikipedia to follow. Ebony Jackson (talk) 03:44, 28 April 2021 (UTC)

For your information, user:Cewbot has been removing vital-article templates from the talk pages of these renamed articles. I suspect that that is a mistake. JRSpriggs (talk) 18:48, 30 April 2021 (UTC)

• Comment. If this change is done then in the disambiguation parentheses (and other contexts where it can reduce potential for confusion) the replacement should be of "recursion theory" by "computability theory", not simply "computability" as was done in some cases. So Forcing (computability theory) not Forcing (computability). 73.89.25.252 (talk) 19:13, 3 May 2021 (UTC)

Not sure I agree - I think Forcing (computability) has exactly the same meaning, is just as unambiguous, plus saves seven characters in the title. --Jordan Mitchell Barrett (talk) 22:46, 1 June 2021 (UTC)

• Comment. I prefer "computable" and "computably enumerable" because they are more readily understood and far less readily misunderstood by strangers to that area of study. One could also make an argument for saying "More than one editor think that" instead of "More than one editor thinks that", on the grounds that "more than one" is plural, but that is not the way the English language conventionally works. The extent linguistic to which convention should govern this present issue is a question about which I am not prepared to argue. Michael Hardy (talk) 15:56, 11 May 2021 (UTC)

• Support. I applaud the change. Every time I would stumble over "recursively enumerable" I would have to stop in my tracks and look up the definition and make sure I wasn't cross-eyed while re-reading it for the 13th time. Whereas the meaning of "computably enumerable" is obvious. So Yay! 67.198.37.16 (talk) 21:46, 26 May 2021 (UTC)

Old featured articles – you can help!

I know a number of you have done great work in saving old math-related featured articles from being delisted at FAR. So I figured it might be useful to put together a list of old FAs within this project's scope that could be in danger of potentially losing their star, in the hope of getting them fixed up before somebody starts the formal delisting process. I've done that below; here are a few thoughts: 1) These articles are not all the same. Some may have no issues at all, while others may be practically unsalvageable. 2) You can read the featured article criteria here. While an FA must meet each criterion, in my experience the most important issue for these old FAs is referencing. Our expectations on inline citations have changed a lot over the past twenty years, so making sure that there aren't vast deserts of uncited text is really important. Fixing up any prose issues is also helpful, as is making sure that the article is still a comprehensive overview of the subject. 3) The year provided is the year of the most recent FAC or FAR. Older articles often require more work, but this is of course only a generalization. This list contains only articles that have not been reviewed in more than ten years. 4) If this sort of work interests you, please come help out at WP:URFA/2020. We have an enormous backlog of old featured articles on all subjects that are in need of review.

Notice given: These are the most urgent priorities. Someone has made a note on the article's talk page that the article may not meet the featured article criteria. Such articles are in danger of being imminently taken to FAR.

1. 1 − 2 + 3 − 4 + ⋯ (2007)
2. Polar coordinate system (2007)

Notice not given: Notice has not yet been given for these articles, so they aren't urgent priorities. Just take a look and see if there are any obvious issues with them that need work. If you feel confident in your understanding of the featured article criteria, feel free to go to WP:URFA/2020 and follow the instructions to either give notice, mark the article as satisfactory, or provide other comments.

1. Archimedes (2007)
2. General relativity (2008)
3. Georg Cantor (2007)
4. Emmy Noether (2008)
5. Introduction to general relativity (2008)
6. 0.999... (2010)
7. Edward Wright (mathematician) (2008)
8. Emery Molyneux (2008)
9. Johannes Kepler (2007)
10. Numerical weather prediction (2011)
11. Problem of Apollonius (2008)
12. Robert Hues (2009)
13. Émile Lemoine (2008)

I hope this list is useful to you all. Getting these FAs taken care of outside the formal process is good for everyone: it reduces the URFA backlog, it gives you all advance notice of potential issues, and it provides an incentive to improve these important articles. Do let me know if I can be of any assistance: while my mathematical expertise is lacking, I'm glad to answer any questions about the FAR process. Cheers! Extraordinary Writ (talk) 18:41, 31 May 2021 (UTC)

Why does it matter if an article is a "featured article" or not? 67.198.37.16 (talk) 05:07, 1 June 2021 (UTC)

While having the articles be as good as they can be is obviously more important than making them meet arbitrary internal milestones, here are two reasons why we might care about this anyway: (1) we want our best mathematics articles to be highlighted as part of the best content on Wikipedia, to bring readers to them, to show the world that mathematics is an important part of Wikipedia, and to bring interest to mathematics more generally, and groupings like FA, GA, and DYK can provide an opportunity to do that, and (2) the pressure to meet the arbitrary milestone can help us improve the articles, especially when they are deficient in obvious ways. —David Eppstein (talk) 06:41, 1 June 2021 (UTC)

Where should one expend effort? One might argue that the energy would be better spent on the most-frequently viewed articles. Another possibility is that all top-priority articles should be made FA. This is balanced by several realities: it is a lot easier to take a low-importance article, and make it FA, than a top-importance article, because the top-importance articles have to say more stuff in exactly the right way, whereas lacunae in low-importance articles are easily overlooked (and, frankly, don't matter). The other reality is that WP is a labor of love: almost all FA articles are created/shepherded by one person who is passionate about that particular topic. If/when that passionate person retires, so does the passion. It's hard (impossible?) for the disinterested bystander to make the kind of edits needed to make an FA article: one is not eating, sleeping and drinking the topic. (Literally. Don't know about you, but when I am creating WP articles I care about, I think about it while I walk the dog, while I fall asleep, when I wake up. All that thinking provides the needed corrections, amplifications and expanded sections. Without this effort, the coverage & content would be just .. meh.) 67.198.37.16 (talk) 17:41, 1 June 2021 (UTC)

Perhaps the reason why the percentage of editors is biased is that it was evaluated as FA when there were few editors on wikipedia. Articles marked FA basically do not need to be edited, and it seems unlikely that an inexperienced editor like me would edit an article marked FA. Creating an article from scratch is difficult, so it seems like we start by editing (on wikipedia) the article in the start-class or C-class article. (stub-class editing is difficult.) I'm not confident in editing articles in B-class and above. Perhaps I wouldn't edit FA-class articles without FAR. (My two cents).--SilverMatsu (talk) 06:48, 2 June 2021 (UTC)

Most viewed start article in this Wikiproject

Missing square puzzle 91,834 3,061 Start--Coin945 (talk) 14:59, 30 May 2021 (UTC)

I have "resolved" this by reclassifying the article as C-class. (The prose is pretty good; the sourcing is very weak, though.) --JBL (talk) 17:32, 30 May 2021 (UTC)

Nice work! However, tonnes of readers are still flocking to this page for information and basing our reputation on it. So, the more comprehensive the better in my books!--Coin945 (talk) 17:58, 30 May 2021 (UTC)

I agree, that looks like a C-class article to me. Also, this just goes to show, views ≠ importance. —David Eppstein (talk) 19:15, 30 May 2021 (UTC)

Fyi here are the 3 most-viewed stub articles in your Wikiproject:--Coin945 (talk) 19:34, 30 May 2021 (UTC)

• Convenience sampling 16,992 566 Stub
• Welch's t-test 16,592 553 Stub
• 1/2 + 1/4 + 1/8 + 1/16 + ⋯ 14,340 478 Stub

And some of the most-viewed starts:--Coin945 (talk) 19:34, 30 May 2021 (UTC)

• Kelly criterion 76,759 2,558 Start Mid --> for the budding gamblers out there?
• 666 (number) 62,452 2,081 Start Low --> for the superstitious lot?
• Sigmoid function 55,424 1,847 Start Low --> maths classes?
• Unit circle 53,839 1,794 Start Mid --> maths classes?
• Bernoulli distribution 51,260 1,708 Start Low --> maths classes?
• Vertical and horizontal 49,311 1,643 --> always a good reminder!

I also re-rated Kelly criterion as C-class, and the three supposed stubs as start-class. —David Eppstein (talk) 16:43, 31 May 2021 (UTC)

By the way, can 1/2 + 1/4 + 1/8 + 1/16 + ⋯, 1/2 − 1/4 + 1/8 − 1/16 + ⋯ and 1/4 + 1/16 + 1/64 + 1/256 + ⋯ be merge? The alternating series are mixed, but I think there is no problem because it converges absolutely. How about the title, such as ′′Infinite sum of multiplicative inverse of Power of two′′?--SilverMatsu (talk) 12:04, 2 June 2021 (UTC)

FAR for Leonhard Euler

I have nominated Leonhard Euler for a featured article review here. Please join the discussion on whether this article meets featured article criteria. Articles are typically reviewed for two weeks. If substantial concerns are not addressed during the review period, the article will be moved to the Featured Article Removal Candidates list for a further period, where editors may declare "Keep" or "Delist" the article's featured status. The instructions for the review process are here. (t · c) buidhe 04:06, 8 May 2021 (UTC)

This has received some attention since the FAR was announced, but it could benefit from more. XOR'easter (talk) 20:36, 24 May 2021 (UTC)

There's a sentence in the article that's confusing me, and I think here may be a better place than the FAR to get an informed opinion: In the applied mathematics section, it states "He also facilitated the use of differential equations, in particular introducing the Euler–Mascheroni constant". My understanding of the Euler–Mascheroni constant is that its primary use is as the constant error term in the approximation of the harmonic series by the logarithm (or, I suppose, vice versa, but that's the usual direction of approximation for me), and that it belongs more to the analysis or maybe analytic number theory sections than in a section on applied mathematics and a sentence on differential equations. But maybe there's an application of this constant to differential equations with which I'm unfamiliar and which the "Appearances" section of Euler–Mascheroni constant doesn't make clear? —David Eppstein (talk) 07:35, 25 May 2021 (UTC)

I agree with you, but I'm also interested in classifying the section names into Riemann zeta functions (Euler zeta function? in Euler's times, complex analysis was not well developed but Euler certainly had the foresight for complex analysis. ) and transcendental number theory (I don't know if it's a transcendental number…), also interested in Euler's infinite series.--SilverMatsu (talk) 14:28, 26 May 2021 (UTC)

I agree — I revised the sentence about the constant and moved it to the analysis section. Also, I'd sort of like to eliminate the "Applied mathematics" section altogether, and redistribute its subjects into other sections. Adumbrativus (talk) 04:03, 27 May 2021 (UTC)

The article has been moved to the Featured Article Removal Candidates section. XOR'easter (talk) 17:45, 6 June 2021 (UTC)

Re: John Rognes (mathematician)

Found in new article queue. Please review and expand at your leisure. Many thanks. --Gryllida (talk, e-mail) 06:52, 7 June 2021 (UTC)

Copyvio in Quadratic reciprocity

The proof of quadratic reciprocity given in Quadratic reciprocity#Proof is a blatant copyright violation: it is a verbatim copy (letter for letter, down to idiosyncracies in the notation) of almost the complete text (only omitting the initial sentence) of the paper Bogdan Veklych, A Minimalist Proof of the Law of Quadratic Reciprocity, The American Mathematical Monthly 126 (2019), no. 10, p. 928, doi: 10.1080/00029890.2019.1655331. (It’s a short paper.) I tried to remove it, but I am being reverted by user Strecosaurus (talk · contribs), who hasn’t got the slightest clue about copyright law and scientific publishing (see talk), but is all the more aggressive for it. Can someone else have a look?—Emil J. 07:38, 9 June 2021 (UTC)

Yes, can please someone else have a look? I'm pretty sure reproduction of a mathematical proof (of all things!) published somewhere is not copyright violation, otherwise no mathematical proof will be legally reproducible after it's found?! — Preceding unsigned comment added by Strecosaurus (talk • contribs) 11:41, 9 June 2021 (UTC)

I've been editing Wikipedia for 7 years (and this section appears to have existed intact for over a year, by the way) and this is the most ridiculous thing I've ever seen. A reproduction of a mathematical proof is forbidden?! What? Then any mathematical proof or definition, once it's found, can never be presented again, because it occurs in the original article, and so reproducing it again would be violating the copyright? Is this the logic?! — Preceding unsigned comment added by Strecosaurus (talk • contribs) 11:50, 9 June 2021 (UTC)

Wow. --JBL (talk) 13:56, 9 June 2021 (UTC)

Yeah, that's way too close a copy to be permissible. Reproducing the logic of an argument is one thing, but carrying over the prose and the notation practically verbatim is another. And the fact that it hung around for a year is immaterial; a problem is still a problem even if people were late to notice it. XOR'easter (talk) 16:10, 9 June 2021 (UTC)

A pointer

Hi, mathematicians! There's a discussion going on about what constitutes a "routine calculation", and I think it would benefit from your input. Please see Wikipedia talk:No original research.—S Marshall T/C 17:08, 12 June 2021 (UTC)

Retarget Complex variables to Complex analysis

Retarget to Complex analysis, and with hatnote to Function of several complex variables. Also delete "Complex variables (disambiguation)". Also see Wikipedia:Redirects for discussion/Log/2021 June 5#Complex variables (disambiguation). thanks!--SilverMatsu (talk) 04:00, 8 June 2021 (UTC)

To be clear, the discussion is invalid in Redirects for discussion (Complex variables (disambiguation)). Apparently, on this page or on the complex variable talk page, the discussion has to be restarted from the beginning. I am sorry to have those who participated in the discussion express their opinions again.--SilverMatsu (talk) 01:14, 9 June 2021 (UTC)

I've summarised the issue at Talk:Complex variables. Interested editors can participate there. --Paul_012 (talk) 18:08, 13 June 2021 (UTC)

Draft:Dirichlet character

A draft, Draft:Dirichlet character, was submitted for review. However, it seems to be a modified version of the article that we already have, Dirichlet character, and Articles for Creation is not the way to propose changes to an existing article. I don't know whether it will be obvious to a mathematician what has changed, let alone whether the changes should be made. I just thought I would call this to your-all's attention. Robert McClenon (talk) 20:55, 13 June 2021 (UTC)

every vs. any vs. arbitrary

For example, I would like some advice about Function of several complex variables#top. I'm wondering whether to make it "any" or "arbitrary". "any" seems to have a similar meaning to "for all" and has been used for one variable (also, "every" was often used) , but several complex variable textbooks and papers often use "arbitrary", so only use for $\mathbb {C} ^{n}$, "arbitrary". Because it feels like arbitrary is randomly selected. There is also an arbitrary complex manifold, but I follow the paper because for several complex variables their nature depends on how the space is taken anyway. Perhaps this is also useful when editing other articles, and I don't understand this well. thanks!--SilverMatsu (talk) 06:01, 30 May 2021 (UTC)

I suggest avoiding "any": it can be used in some situations for both existential and universal quantifiers in normal speech, so is confusing about which formal statement it corresponds to. (For example, "if any x satisfies F(x) = 0" as a stand-alone phrase could mean "if every x satisfies F(x) = 0" or "there exists an x such that F(x) = 0", depending on context.) "An arbitrary" may suffer from the same problem, again depending on context. "Each", "every", and "for all" do not have this problem. They have different grammatical behaviors, so which one to use is largely a question of writing style (does the sentence work better with a singular or a plural?).
The current lead section of Function of several complex variables has much more serious grammatical/language issues than this choice. At some point hopefully it will be copy-edited by a fluent English speaker, who will have the opportunity to patch this up. Personally, I would write "For one complex variable, every domain $D\subset \mathbb {C}$ is the domain of holomorphy of some function. For several complex variables, this is not the case, and so ...." Or, if I wanted to really drive home the point: "For one complex variable, every domain $D\subset \mathbb {C}$ is the domain of holomorphy of some function. For several complex variables, this is not the case: there exist domains that are not the domain of holomorphy of any function, and so ...." -JBL (talk) 11:36, 30 May 2021 (UTC)

It's surprising that Wikipedia:Manual of Style/Mathematics does not give advice on this issue. Mgnbar (talk) 12:56, 30 May 2021 (UTC)

Thank you for the advice and reply. I edited it a little and replaced it with "every". I agree that the Manual of Style needs advice. Also, apparently there is a page of the arbitrary, but there was no template for WikiProject Mathematics. Replacing "arbitrary" seems difficult about Levi's problem statement seems difficult. For example; each complex manifold chosen for arbitrary? --SilverMatsu (talk) 15:32, 31 May 2021 (UTC)

Existential quantifiers can also sometimes be replaced by verbs of possession: "every domain has a function for which it is the domain of holomorphy". —David Eppstein (talk) 19:49, 31 May 2021 (UTC)

Thank you for the advice. It's an interesting. By repeating the paraphrase, it becomes clear.--SilverMatsu (talk) 11:32, 1 June 2021 (UTC)

English-speaking mathematicians use "any" too much. They forget that in some contexts, it means "some" rather than "every". "If every A is B then...." is clear. "If any A is B then..." might mean "If there is any A that is B, then..." or it might mean "If it is the case that any A, no matter which one, is B, then..." In the first case, it means "some"; in the second, it means "every". Michael Hardy (talk) 04:38, 6 June 2021 (UTC)

Thank you for the advice. Even if the paper uses "any", I will now try to choose clearer words when quoting to wikipedia--SilverMatsu (talk) 03:28, 15 June 2021 (UTC)

 Done I boldly added a note based on JayBeeEll's example at the end of Mathematics#Writing_style_in_mathematics, which seems the most appropriate place to me. Please improve if necessary. - Jochen Burghardt (talk) 15:13, 15 June 2021 (UTC)

Thank you!--SilverMatsu (talk) 03:10, 16 June 2021 (UTC)

Feature request on Phabricator

I've submitted a feature request on Phabricator for continuous numbering and cross-referencing of list items. The request itself concerns example numbering in linguistics articles, but I suspect this functionality would be useful for theorem numbering in mathematics articles as well. If you would support this idea or if you would like to add anything to the feature request, you can leave a comment at the Phabricator page. Alternately, if anybody has any handy tricks or secret workarounds using currently existing features, please do share! Botterweg14 (talk) 15:19, 16 June 2021 (UTC)

The 10 most-viewed, worst-quality articles according to this Wikiproject

• 910 Nim 13,375 431 Unknown Unknown
• 31 Charles Hoskinson 99,039 3,194 Start Unknown
• 88 666 (number) 61,931 1,997 Start Low
• 131 Sigmoid function 52,201 1,683 Start Low
• 156 Bernoulli distribution 47,010 1,516 Start Low
• 188 Dependent and independent variables 43,152 1,392 Start Mid
• 196 Breadth-first search 41,806 1,348 Start Mid
• 224 Eric Weinstein 38,784 1,251 Start Low
• 226 Googol 38,581 1,244 Start Low
• 230 Transpose 38,176 1,231 Start Mid

Wikipedia:WikiProject Mathematics/Popular pages--Coin945 (talk) 07:16, 19 June 2021 (UTC)

I don't know why you list Nim as unrated. An anonymous editor just rated it as C-class, two weeks ago. I agree (it's too detailed for start-class and has too much unsourced content to be B-class). —David Eppstein (talk) 07:29, 19 June 2021 (UTC)

I'm pulling data from Wikipedia:WikiProject Mathematics/Popular pages - it was listed as 'Unknown' there. --Coin945 (talk) 08:19, 19 June 2021 (UTC)

FAR for Polar coordinate system

I have nominated Polar coordinate system for a featured article review here. Please join the discussion on whether this article meets featured article criteria. Articles are typically reviewed for two weeks. If substantial concerns are not addressed during the review period, the article will be moved to the Featured Article Removal Candidates list for a further period, where editors may declare "Keep" or "Delist" the article's featured status. The instructions for the review process are here. Z1720 (talk) 14:39, 19 June 2021 (UTC)

RM Trapezium and Trapezoid

Members of this project may find Talk:Trapezium and Trapezoid#Requested move 21 June 2021 interesting.--Eostrix  (^{🦉 hoot} _hoot🦉) 16:05, 21 June 2021 (UTC)

Requested move: Indecomposable → Indecomposability (disambiguation)

A RM was started at Talk:Indecomposable; discuss there if interested. (I'm posting a notice here since it's about mathematics but is not in the article alerts.) Adumbrativus (talk) 07:56, 22 June 2021 (UTC)

I would like to create a Hartogs' Inverse Problem as a redirect of Levi's problem

Oka calls Levi problem. problème inverse de Hartogs. Hartogs shows Oka's lemma in the case of two variables, which is Hartogs's problem, and Levi's problem is the opposite. And the problem of Levi problem has various meanings now. (e.g. Stein manifold, Complex projective space, Stein space, etc.) Oka's proof is an unramified Riemann domain ($\mathbb {C} ^{n}$), so this term may also accurately refer to Oka's achievements. thanks!--SilverMatsu (talk) 16:37, 16 June 2021 (UTC)

I added it to Oka's lemma because there is an aspect that Oka called it. Would you like to redirect to Oka's lemma lemma?--SilverMatsu (talk) 02:30, 19 June 2021 (UTC)

Addendum 1; Perhaps the decision to create a redirect depends on how English-speaking mathematicians often call Levi's problem. From the same point of view, we can decide whether to send the Draft:Gaussian symbol to MfD vs. RfD.--SilverMatsu (talk) 03:16, 19 June 2021 (UTC)

Addendum 2; For drafts, it seems that in some countries the symbol representing the floor function is called the Gaussian symbol, and if English-speaking mathematicians do not use this term often or use it in a different sense, send it to MfD.--SilverMatsu (talk) 07:34, 19 June 2021 (UTC)

I noticed that the draft:Gaussian symbol was translated from Chinese wikipedia, so check Babel and ping MarkH21.--SilverMatsu (talk) 02:03, 24 June 2021 (UTC)

reference

• Noguchi, Junjiro (2018). "A Brief Chronicle of the Levi (Hartogs' Inverse) Problem, Coherence and an Open Problem". arXiv:1807.08246. {{cite journal}}: Cite journal requires |journal= (help)
• Oka, Kiyoshi (1953). "Domaines finis sans point critique intérieur". Japanese Journal of Mathematics. 27: 97–155. doi:10.4099/jjm1924.23.0_97. PDF TeX

about Euclid's theorem

I would like to some advice about the edit warring. I tried to avoid the Euler product argument when it was Re(s) = 1. thanks!--SilverMatsu (talk) 10:39, 29 June 2021 (UTC)

I forgot to write a set. perhaps, If P is the set of all prime numbers and the prime number set (set P) is finite set …--SilverMatsu (talk) 11:09, 29 June 2021 (UTC)

1. This is what article talk-pages are for: you made a bad edit, it was reverted, you should now begin discussion on the article talk-page if you want to reach consensus. 2. Have you considered instead editing Wikipedia in whatever your native language is? I suspect you could be a valuable editor there. --JBL (talk) 11:59, 29 June 2021 (UTC)

Thank you for your advice. I apologize for my lack of ability, but I will try my best.--SilverMatsu (talk) 13:33, 29 June 2021 (UTC)

Dirichlet character

I have rewritten the article Dirichlet character.

A number of years ago I edited several number theory articles including Quadratic reciprocity, Arithmetic function, and Floor and ceiling functions under the name Virginia-American. The computer died, I lost my password, etc., and finally now I'm back under a new handle.

Could someone who knows the conventions please add categories, ratings, and so forth?

Thanks

James in dc (talk) 21:33, 30 June 2021 (UTC)

Jul 2021

RfC of interest

This RfC may be of interest to members of this group. Beyond My Ken (talk) 04:03, 1 July 2021 (UTC)

Bold or italic for terms to be defined

Is there any guidance or established consensus on whether to put terms that are defined in bold or in italic? The model theory article, for instance, mainly uses boldface, but not where terms are wikilinked, while the featured article group (mathematics) uses italic. I am sorry of this had been discussed in the past or if it is included in the relevant Manuals of Style; I could find it in neither place. Felix QW (talk) 15:05, 1 July 2021 (UTC)

The advice at MOS:NOBOLD and MOS:WAW suggest italics is preferred. My personal advice is not to do wholesale changes just to change a formatting issue like this. (But if you're making other, substantive changes to an article, and you incidentally bring the formatting into accordance with MOS, that seems fine.) --JBL (talk) 15:12, 1 July 2021 (UTC)

Thank you very much! That was exactly the sort of advice I was looking for! Felix QW (talk) 15:17, 1 July 2021 (UTC)

To editor Felix QW: However, this is a recommended practice to use boldface for the target of a redirect (this helps readers that follow the redirect to find the target). This may explain why some terms are defined in bold and some other in italic, in the same article. D.Lazard (talk) 16:11, 1 July 2021 (UTC)

Indecomposability (constructive mathematics)

Please look at Indecomposability (constructive mathematics) and its talk page. Clearly the anonymous user who started the discussion on the talk page is right that the page as written now cannot be understood without some context that mmost people do not have and that the article does not provide. I am rusty in this stuff. Michael Hardy (talk) 23:42, 3 July 2021 (UTC)

I have changed "constructive mathematics" into "intuitionistic logic" in the article title and in the first sentence. This does not provide much more context, but clarifies that this article does not belong to the standard logic. Also, this is supported by the titles of all sources. D.Lazard (talk) 07:59, 4 July 2021 (UTC)

Tilings and polyhedra

Currently dual tiling redirects to dual polyhedron, which has some relevant images but does not treat the topic in its main text. I'm inclined to think we would be better off with either a new article, or changing the redirect to dual graph. I've raised the matter here rather than on the respective talk page, because it touches on quite a few articles.

There's an analogous problem with our templates, which I've raised at Template talk:Infobox polyhedron. — Charles Stewart (talk) 08:33, 5 July 2021 (UTC)

It seems there are two sections that talk about dual tessellations/tilings: Dual_graph#Infinite_graphs_and_tessellations and Tessellation#Voronoi_tilings. I guess the redirect target would depend on whether one is concerned about topological dual graph aspect or the geometric dual tiling aspect of a dual tiling. A separate article explaining both may be a good idea. --{{u|Mark viking}} {Talk} 09:50, 5 July 2021 (UTC)

Proposal

I propose expanding List of fractals to include more information so that it looks like this and then moving the page to Table of fractals. Thoughts? Please respond here. ➧datumizer  ☎  19:09, 5 July 2021 (UTC)

Torsion of a curve: Are the "Definition" and "Alternative description" intended to be equivalent?

Would anyone here know the answer to this question? —2d37 (talk) 09:24, 9 July 2021 (UTC)

Proposed merge of Angular measurement to Angle

There is a merge discussion at Talk:Angle#Merger of Angular unit into Angle#Units. — Cheers, Steelpillow (Talk) 18:12, 9 July 2021 (UTC)

Questionable short descriptions

I have not followed closely the appearance and evolution of short descriptions, but I know some of you do. Those who care might want to check out the contributions of User:Hashirkashif123, who has been adding or editing a lot of short descriptions in articles related to mathematics. I would not say that all of their contributions are bad, but a significant number seem questionable. --JBL (talk) 13:46, 7 July 2021 (UTC)

This user has edited approximately 150 short descriptions in three days. All those that I have looked at are either nonsensical, or definitively wrong or violate the style rules of short desciption. Apparently, Hashirkashif123 did not read the warnint that I have posted on their talk page. They must be stopped. I'll post at WP:ANI. D.Lazard (talk) 14:04, 7 July 2021 (UTC)

D.Lazard was successful, and they have been blocked indefinitely. --JBL (talk) 21:01, 7 July 2021 (UTC)

As the edit tags show that Hashirkashif123 was using a mobile app, I suspect this may have been a case of WP:THEYCANTHEARYOU. (For anyone else who tried to find the report at ANI and couldn't: it was Special:Diff/1032450732 and the resolution was Special:Diff/1032480581.) —2d37 (talk) 00:19, 10 July 2021 (UTC)

I've only (relatively) recently become aware of WP:THEYCANTHEARYOU with regard to mobile app editing. This seems like a MAJOR PROBLEM. Does anyone know if this is being addressed? Paul August ☎ 00:40, 10 July 2021 (UTC)

No, because it requires work from the Wikimedia developers and they can't hear you either. The inability to communicate with mobile users has been flagged as a problem as far back as 2015 [6] but it keeps getting marked as low priority with nothing done, or worse in some cases like the one I linked closed as intentional behavior rather than being considered a bug. Maybe if we started implementing a policy of blocking mobile users on first offense, rather than trying unsuccessfully to communicate with them, someone might take notice? —David Eppstein (talk) 01:36, 10 July 2021 (UTC)

I've gone through Hashirkashif123's contributions, and unless I'm a terrible judge of character, it really did seem to me that there wasn't ill intent... I think the ban might have been unfair. As for David Eppstein's solution, I've seen (in just a month or so here) my share of fools who I know should be banned at first offense, and I'm largely in favor of starting a fire to call the firefighters. I just hope that targeting mobile users specifically isn't setting fire to the orphanage. Horsesizedduck (talk) 18:22, 11 July 2021 (UTC)

Inverse limit

See Talk:Inverse limit#Difficult to use and incommensurate with parallel articles — since February, User:Mgkrupa has been making hundreds of edits to this article, making it more technical to the point of unreadability and causing multiple other editors to complain. I have reverted back to the February version, but I suspect the dispute is not over. Please participate in the discussion or on the article, especially if you are interested in both category theory (not really my thing, but I won't judge you for liking it if you do) and the accessibility of our mathematics articles. —David Eppstein (talk) 02:01, 12 July 2021 (UTC)

Ooof. My eyes glazed over. However, this skirts an issue that has long fascinated me: what would it take (would it be possible) to make at least some WP articles be "review" articles? By "review", what I have in mind are the 20-40 page articles you might find in "mathematical reviews", or as classroom handouts written by the prof (e.g. the assorted PDF's that can be found online, emanating as "lecture notes" from assorted universities). Currently, this is impossible in WP for only one reason: there is not enough manpower available to actually read through and pick apart a long article. For example, I have no doubt that I could "easily" understand this version of inverse limits, although my "easy" understanding might take several 8-hour days of careful reading and cautious thinking. That's a whole lot of effort. It's free time I don't have (aka time I don't want to devote to this). A secondary concern is that there is no particular "seal of approval" that would indicate that two outside experts did cautiously and carefully vet the article. Without this, we'd risk having the usual OR and fringe-science issues get further magnified, making maintainability even harder, while eroding trust.

However, there does seem to be a nascent effort in this direction. See Category:Wikipedia articles published in peer-reviewed literature. I support that effort. Thus, I would like to suggest that mgkrupa should take the long version, reinstate the easier-to-understand introduction, submit the finished product to an appropriate journal (where?????) and wait for a comprehensive reply. Then would could have a long and through article that would provide details, and would be acceptable as quality content.

The gotcha here is the actual process: the details: what journal? The Wiki Journal of Science? Is their editorial staff well-connected enough to find suitable peer reviewers? What, exactly, is the relationship to WP? I'd like to see this stuff work. The effort seems daunting, but the results, done right, would be worth the effort. 67.198.37.16 (talk) 19:12, 13 July 2021 (UTC)

The correct link for the WikiJournal of Science is this. There have been a few articles published that are relevant to this WikiProject: [7], [8], [9], [10]. Some of these have been tied to Wikipedia, others have not. Since it's open peer review, you can assess directly whether the reviewers were appropriate. (In the case of the affine symmetric group, they clearly were.) --JBL (talk) 19:24, 13 July 2021 (UTC)

Orientation (mathematics)

Orientation (mathematics).

I have qualms about the present state of this article. What is the relationship to chirality? Michael Hardy (talk) 16:02, 15 July 2021 (UTC)

"Orientation" has two different meanings in mathematics. So Orientation (mathematics) must be a redirect to the dab page Orientation#Mathematics. The first meaning corresponds to the common language meaning, and is described in Orientation (geometry). It can take infinitely many valiues, parametrized by Euler's angles. The second meaning can take only two values, $+$ and $-,$ and is related to chirality, but is much more general, as chirality refers only to the orientation of the three-dimensional Euclidean space. This concept of orientation is the subject of Orientability. Apparently, the editors of Orientation#Mathematics and Orientation (geometry) ignore this distinction.

I'll try to fix this mess by creating a redirect Orientation (space) to Orientability, and fixing the disambiguation pages. D.Lazard (talk) 16:47, 15 July 2021 (UTC)

Draft:Sparsity matroid

Could someone here please take a look at it, and either accept it themselves or advise me what to do or say. DGG ( talk ) 23:22, 16 July 2021 (UTC)

I think it's a notable topic, although possibly I'm biased because it overlaps some topics in my research. There's a fair amount of overlap with Dense graph#Sparse and tight graphs, but that's not really a problem for having a separate article. I'm not sure "sparsity matroid" is the right title, though, as it's really about (k,l)-sparseness and (k,l)-tightness, and only some subset of combinations of the two parameters give matroids. Maybe split off the current redirect sparse graph into a separate article? Some copyediting is needed (e.g. references after punctuation). —David Eppstein (talk) 23:40, 16 July 2021 (UTC)

Also Draft: Bose integral, though I suppose it must be covered elsewhere, in which case we need a redirect. DGG ( talk ) 06:40, 17 July 2021 (UTC)

I can do both of these. — Charles Stewart (talk) 06:50, 17 July 2021 (UTC)

Hilbert space referencing

Hilbert space is a Good Article on an obviously-important topic, and to me the writing looks in good shape, but the referencing is a little patchy, with some parts of the article not clearly sourced to any reference. If anyone here cares to work on better referencing for the article, that would be helpful, and possibly save the article from undergoing a Good Article Review. —David Eppstein (talk) 18:37, 17 July 2021 (UTC)

I provided references for some of the quantum-mechanics statements using the books I currently have near at hand. XOR'easter (talk) 17:41, 18 July 2021 (UTC)

List of computer algebra systems

There have been recent attempts to add links to drhuang.com to several mathematics pages. As the site does not look either especially helpful, nor otherwise good to have, and as I've had concerns about promotionalism, I've tended to remove these when I come across them. The recent attempt to add such a link (together with a new, little-known CAS) to List of computer algebra systems has been especially determined, with some edit-warring to keep the material. It is possible that it is appropriate and WP:DUE to add something. I'd appreciate some additional sets of eyes on the page. Russ Woodroofe (talk) 16:02, 18 July 2021 (UTC)

I have also removed some of these links. The assertion of their authors that it is a computer algebra system is unverifiable, as no indication is given on the used algorithms, and no citation by external sources are provided. So, this software does not pass any of our criteria for WP:Verifiability and WP:Notability, and the link to its web page must be removed for these reasons, and also WP:ELNO. D.Lazard (talk) 18:08, 18 July 2021 (UTC)

Draft: Reilly formula

An admin says that a page I submitted a while ago, en.wikipedia.org/wiki/Draft:Reilly_formula, will be accepted if I "add a sentence or wo of background about Reilly, and information about where he published the formula." I'm not editing wikipedia any more but thought somebody might like to add it. Gumshoe2 (talk) 22:18, 17 July 2021 (UTC)

@Gumshoe2: Is it okay for this article to have an external link section? senate.universityofcalifornia.edu/in-memoriam/files/bob-reilly.html--SilverMatsu (talk) 04:21, 21 July 2021 (UTC)

Cayley–Menger determinant - request for verification

Please see and verify this edit: special:diff/1033122327. That's not my area but the change looks somewhat ...strange to me. --CiaPan (talk) 18:26, 21 July 2021 (UTC)

Seems plausible to me - At least in the spherical case the inline citations speak of a sphere of radius R, and that should have curvature 1/(R^2). Felix QW (talk) 18:55, 21 July 2021 (UTC)

Order dual

Until about a year ago, the article Order dual was a redirect to Duality (order theory). Then User:Mgkrupa wrote an article on a different subject (as usual, something about topological vector spaces). I believe that all links to Order dual are from within the topological vector spaces walled garden that Mgkrupa constructed (so that no incoming links are intended to go to Duality (order theory)), but I would be grateful if someone else could double-check that. (This was prompted by this edit.) --JBL (talk) 16:20, 24 July 2021 (UTC)

I changed it back. Let me know if there are any issues and I'll try to resolve them. Mgkrupa 17:44, 24 July 2021 (UTC)

Also, all of the links that were leading to Order dual were functional analysis related (and have since been appropriately updated) with the exception of: Wikipedia talk:WikiProject Mathematics, Wikipedia:WikiProject Mathematics/List of mathematics articles (M–O) , Wikipedia:WikiProject Mathematics/List of mathematics articles (O), and Talk:Order dual. Mgkrupa 18:09, 24 July 2021 (UTC)

I've updated the redirection page Order dual so that it now redirects to the disambiguation page for term "order dual", which is appropriate since there are several concepts that go by that name. Mgkrupa 19:08, 24 July 2021 (UTC)

Thanks, this name shuffle seems like a good resolution. --JBL (talk) 02:05, 28 July 2021 (UTC)

Recent creations of questionable notability

I stumbled across the recently created stub Mathematics and nursing, and it seems that the author (new user Nicolasatasan) has been producing a bunch of articles on individual mathematics competitions (Spanish Mathematical Olympiad, etc.) and other topics of dubious notability relating to mathematics. (Might Wikipedia:Articles for deletion/Nicolás Atanes be related? I'm not sure.) Without wishing to overly discourage a brand-new editor (WP:BITE), perhaps others might like to take a look. --JBL (talk) 02:05, 28 July 2021 (UTC)

There probably is a notable topic here. I've tutored a couple of nurses through the mathematics part of their course. One of the most important aspects is dosage calculation, they have to work out the right dosage for a given body weight, and they have to get this right 100% of the time. See for example nursing dosage calc. Plenty of online and offline references for the topic. --Salix alba (talk): 09:47, 28 July 2021 (UTC)

I am skeptical that the right title for an article about dosage calculations is "Mathematics and nursing". In any case, the creator turns out to a banned sock-puppet (related to the AfD I mentioned) and so the articles have been deleted per WP:CSD#G5. --JBL (talk) 15:13, 29 July 2021 (UTC)

@JayBeeEll: It is probable that far more is involved than dosage calculations but that the creator of the article didn't know how to explain that. Michael Hardy (talk) 19:47, 31 July 2021 (UTC)

Laws of Indices

The page Laws of Indices has existed as a redirect to Exponentiation since 2005. Bcp67 just added a disambiguatory hat-note (apparently there's also a horse by the same name) and then D.Lazard removed the hat-note and retargeted the redirect to the horse. A quick pop into a search engine suggests that in some versions of English (not mine) "indices" may be synonymous with "power" or "exponent"? (So that "Laws of indices" means the same as "Exponent rules".) Does anyone know what versions of English that might be? Should there be a disambiguatory hat-note on the horse article pointing to Exponentiation? --JBL (talk) 19:59, 29 July 2021 (UTC)

I think this case is similar to f(x). I haven't thought enough about the relationship between the two cases, so it might be a pseudo. Apparently, the disambiguation page isn't working well this time either. Would they like to redirect to the disambiguation page and then display it in hatnote of a article Exponentiation? By the way there seems to be power (horse).--SilverMatsu (talk) 21:32, 29 July 2021 (UTC)

It feels more like number theory to call the x part of $a^{x}$ a index. see Primitive root modulo n.--SilverMatsu (talk) 00:02, 30 July 2021 (UTC)

Yes, this terminology does appear in number theory. See not just Primitive root modulo n but also Index calculus algorithm. I don't know the history, but I wouldn't be surprised to learn that this is an archaic term gone out of fashion. Mgnbar (talk) 00:44, 30 July 2021 (UTC)

When I was working as a school teacher in England (which was two years ago), colleagues did indeed refer to exponent rules as the "laws of indices". I believe this terminology is used at least in Britain in secondary (pre-16) and vocational education, with the modern mathematical terminology used in academic sixth form (16-18). See e. g. https://qualifications.pearson.com/content/dam/pdf/GCSE/mathematics/2015/specification-and-sample-assesment/gcse-maths-2015-specification.pdf Felix QW (talk) 08:25, 30 July 2021 (UTC)

I would suspect that a significant number of pupils would search for it on Wikipedia, perhaps more than for the Irish racehorse.Felix QW (talk) 08:49, 30 July 2021 (UTC)

I have no opinion whether the term "Laws of indices" should be mentioned in WP. If it is mentioned, WP:LEAST implies that Laws of indices should be a redirect to an anchor (note also that the present title is miscapitalized). This is for making this redirecting to an anchor easier that I have not moved Laws of Indices (horse) to Laws of Indices. By the way, Exponent rules was also a redirect to Exponentiation, where the term was not defined. I have added an anchor, and redirected to it, but I am not sure whether these three rules is the complete list of rules that are called "exponent rules". For example, I ignore whether $x^{-a}=1/x^{a}$ should also be included. D.Lazard (talk) 09:21, 30 July 2021 (UTC)

I've created Laws of indices (little i, plural) Law of indices (little i singular) and a redirect to Exponentiation#Identities and properties. These terms used very frequently in the UK mathematics GCSE curriculum, see for example bbc bitesize. It is definitely a valid search term. Page views are pretty low, less than 5 a day. So I'm not sure if adding redirect notices is worth it. --Salix alba (talk): 10:00, 30 July 2021 (UTC)

I've redirected Laws of Indices to Exponentiation#Identities and properties and put a hatnote at the top of Exponentiation. Michael Hardy (talk) 20:47, 31 July 2021 (UTC)

Aug 2021

GA reassessment for Exponentiation

Exponentiation, an article that you or your project may be interested in, has been nominated for an individual good article reassessment. If you are interested in the discussion, please participate by adding your comments to the reassessment page. If concerns are not addressed during the review period, the good article status may be removed from the article. Urve (talk) 09:31, 5 August 2021 (UTC)

Inverse relation, now a disambiguation page

I found that Inverse relation was a redirect page that had been created by means of a move of a page with that title to Converse relation. The latter pages says that if ${\textstyle a\operatorname {R} b}$ if and only if ${\textstyle b\operatorname {S} a}$ then the relation S is the "converse" of the relation R. I found that some articles linked to this redirect page without being intended to link to that topic. So I changed the redirect to a disambiguation page, as follows:

In mathematics, the term inverse relation may refer to either of the following:

• Converse relation
• Inverse proportionality

But then I observed that one of the articles linking to this page is Bernoulli number, which contains this:

${\begin{aligned}B_{n}&=\sum _{k=0}^{n-1}{\binom {n-1}{k}}{\frac {n}{4^{n}-2^{n}}}E_{k}&n&=2,4,6,\ldots \\[6pt]E_{n}&=\sum _{k=1}^{n}{\binom {n}{k-1}}{\frac {2^{k}-4^{k}}{k}}B_{k}&n&=2,4,6,\ldots \end{aligned}}$

These conversion formulas express an inverse relation between the Bernoulli and the Euler numbers.

• Should that be a third item on the disambiguation page?
• Should there be others?
• Why is "converse" a better name than inverse? In particular, the article titled Abstract rewriting system uses the term "inverse relation" to refer to what this page move calls a "converse relation", and links to Inverse relation, now a disambiguation page. Should that word be changed to "converse"? I think not, because here's what it says:

  $\leftrightarrow$ is $(\rightarrow )\cup {(\rightarrow )^{-1}}$, that is, the union of the relation → with its inverse relation, also known as the symmetric closure of $\rightarrow$.

  I understood that immediately, but I would have struggled with it if I'd seen the word "converse".
  
  So how do we deal further with this? Michael Hardy (talk) 16:51, 4 August 2021 (UTC)

  My two cents:

  1) I'd suggest to unlink it. In that case, removing the word "inverse" might actually make it clearer.

  2) There are nine links in to inverse relation. I think most should point to converse "relation".

  3) I suggest you open a move request to see if there is consensus to move "Converse relation" back to "inverse relation". The move was mentioned in the talk page (see here), but there wasn't much of a discussion. Vpab15 (talk) 17:07, 4 August 2021 (UTC)

The link to inverse relation in Bernoulli number is misleading. I don't see how the definition at the former page (or, more generally, that at relation (mathematics)) would be applicable at the latter. Therefore, I changed the sentence to "... express a connection between ...". - Jochen Burghardt (talk) 11:28, 7 August 2021 (UTC)

About change of category name Category:Several complex variables

I tried again in the correct talk page. see Category talk:Several complex variables thanks!--SilverMatsu (talk) 10:34, 8 August 2021 (UTC)

Zero not displayed properly

Tracked in Phabricator
Task T289218

At Wheel theory#Definition, the digit 0 that should result from the markup <math>0</math> is not displayed properly. This is a bug, which has now been tracked on Phabricator. GeoffreyT2000 (talk) 00:23, 19 August 2021 (UTC)

Same thing resulted in recent edits on Binary search algorithm, a featured article. It is important to be able to display 0 as a formula, to match other uses of 0 in larger formulas — 0's in text, without the math formatting, look too different. —David Eppstein (talk) 05:10, 19 August 2021 (UTC)

In Wheel theory, I fixed this by changing the code to \,0. Michael Hardy (talk) 15:35, 23 August 2021 (UTC)

I changed this to {}0 which is another workaround, and doesn't yield extra space. - Jochen Burghardt (talk) 16:48, 23 August 2021 (UTC)

Also (from the binary search edits) just putting a space inside the math markup — <math> 0</math> — works. —David Eppstein (talk) 17:04, 23 August 2021 (UTC)

In fact, the error occurs only if 0 is the unique character inside <math>. So, in multivariate calculus, I fixed the problem simply by moving the punctuation inside <math>. D.Lazard (talk) 17:53, 23 August 2021 (UTC)

Move request for Template:Maths rating

See the discussion at Template talk:Maths rating#Requested move 27 August 2021 which is considering moving
Template:Maths rating → Template:WikiProject Mathematics
Johnuniq (talk) 07:37, 29 August 2021 (UTC)

Sep 2021

Requested move at Talk:Intersection form (4-manifold)#Requested move 26 August 2021

There is a requested move discussion at Talk:Intersection form (4-manifold)#Requested move 26 August 2021 that may be of interest to members of this WikiProject. ASUKITE 16:06, 3 September 2021 (UTC)

New article

Hydra game was recently created over a redirect to Goodstein's theorem. Although I know nothing of this subject area, I am wondering if there should be some tie-in between the articles. Hydra game could be linked in Goodstein's. What about in the other direction - should Goodstein's be listed in a See also section? MB 15:40, 5 September 2021 (UTC)

Thanks for pointing that out. I added it to a See also section, as there is a relation there. --{{u|Mark viking}} {Talk} 18:02, 5 September 2021 (UTC)

about n00,000 articles

Can anyone review a recently created article related to n00,000? These lists contain a lot of square number lists, and if they move them to the square number list, it seems like these articles can be merged.--SilverMatsu (talk) 12:10, 8 September 2021 (UTC)

A bold IP editor recently added squares to 100,000 and split the resulting large article. Discussion is still in progress at WT:WikiProject Numbers#Squares and its following section. Certes (talk) 12:16, 8 September 2021 (UTC)

Thank you for informing me. According to the discussion, the list of numbers that has nothing to mention other than being a square number seems to be good to remove from the article.--SilverMatsu (talk) 12:48, 8 September 2021 (UTC)

list

• 100,000
• 200,000
• 300,000
• 400,000
• 500,000
• 600,000
• 700,000
• 800,000
• 900,000

Thanks for bringing this up here. Yes please someone merge them back together and de-cruft. —JBL (talk) 12:16, 8 September 2021 (UTC)

Done. Further improvements welcome. Certes (talk) 15:39, 9 September 2021 (UTC)

Alternating factorial

I think I understand the difference between Alternating factorial and 1 − 1 + 2 − 6 + 24 − 120 + ... (former target of Alternating factorials), but the topics seem closely related and confusingly similar. Please could someone with a deeper understanding either wikilink them to each other with an explanation of the distinction, or even consider merging them? Thanks, Certes (talk) 22:51, 7 September 2021 (UTC)

@Certes: A merge is a viable solution here. Alternating factorial is about the partial sum (i.e. with n set to a positive integer), while 1 − 1 + 2 − 6 + 24 − 120 + ... (current target of Alternating factorials) is about the infinite sum (i.e. with n set to infinity). They can also be separate articles as long as they talk about each other. — MarkH₂₁^talk 06:10, 8 September 2021 (UTC)

Agreed. The other distinction (if I'm reading correctly) is that the partial sum is always positive but the series leading to the infinite sum has negative values for odd n, i.e. the infinite sum is the limit (insofar as a divergent series has one) of $(-1)^{n}p_{n}$ where p are the positive partial sums from the other article. Certes (talk) 08:24, 8 September 2021 (UTC)

@Certes: Yes, there is the extra alternating sign change for Alternating factorial. For now, I've retargeted Alternating factorials to Alternating factorial and placed a hatnote directing the two articles to each other. This is just a low effort solution though - feel free to add more connecting the two (or even a merge). — MarkH₂₁^talk 03:31, 11 September 2021 (UTC)

Classification theorem as a list article?

Should Classification theorem be converted into a list article at List of classification theorems? It's currently an unreferenced hybrid that attempts to define a classification theorem as a concept and then lists examples. — MarkH₂₁^talk 09:13, 16 September 2021 (UTC)

Note: it seems to have originally been a disambiguation page by Oleg Alexandrov that was then converted into an article by Nbarth (all of this was 15 years ago). — MarkH₂₁^talk 09:14, 16 September 2021 (UTC)

There should be a page on wikipedia explaining the concept of classification in mathematics, which is a central goal of the entire subject across many different areas. I think we should split classification theorem into Classification (mathematics) discussing and describing the concept of a mathematical classification, and List of classification theorems with a (much expanded) list as you propose.Tazerenix (talk) 09:49, 16 September 2021 (UTC)

I agree with the creation of Classification (mathematics), but I am not sure that List of classification theorems is a good idea: most structure theorems and most "fundamental theorems" can be viewed as classification theorems. For example, the fundamental theorem of algebra provides a classification of polynomials by the multiset of roots multiplicities. Also, classical Galois theory classifies algebraic number fields by their Galois group. So, a large part of the important theorems of mathematics should be listed in List of classification theorems, an impossible task! D.Lazard (talk) 10:53, 16 September 2021 (UTC)

If there isn't a page of a list of classification theorems, any page describing classification is going to include a big list anyway (as classification theorem currently does). Perhaps we could make a list page but restrict it to theorems that are very obviously classifications (although this is not particular satisfying for exactly the reasons you made)?Tazerenix (talk) 12:12, 16 September 2021 (UTC)

Yes, almost any important theorem can be viewed as a classification theorem. But for the even broader class, we have big list articles like List of theorems and sublists like List of fundamental theorems. An inclusion criterion can be that the theorem has to actually be called a classification theorem? I'm not sure. — MarkH₂₁^talk 16:11, 16 September 2021 (UTC)

About Domain and Region

Especially in complex analysis, these are used interchangeably and are discussed in Talk:Domain (mathematical analysis)#‎Merge discussion (Domain and Region). thanks!--SilverMatsu (talk) 23:15, 20 September 2021 (UTC)

done.--SilverMatsu (talk) 06:23, 23 September 2021 (UTC)

Polyhedron/Johnson solid situation

There is ambiguity to whether or not uniform polyhedra are considered Johnson solids. Wikipedia tends to claim they do not. But the page "List of Johnson Solids" has recently been reformatted (vandalized?) to include them and uses a different ordering, cutting it off before all 92 solids can be named (because otherwise there would be more prismatics than non-prismatics). All metric information was also removed, leaving only piece counts.

I posted more about this on WikiProject Polyhedra (link) but it turns out that WikiProject Polyhedra is inactive.

73.220.135.34 (talk) 00:41, 23 September 2021 (UTC)

It's the work of a persistent block-evading and IP-hopping vandal. I have protected the Johnson solid article against anonymous users to forestall continued attacks of the same nature. Unfortunately this also shuts out good-faith anonymous editors such as the one who left the comment above. More unfortunately, the attacks also extended to the article talk page, which I also protected (for a shorter time, hoping that this will be enough). So if you have constructive changes to suggest to the article, they may need to be made elsewhere for now; alternatively, I would encourage you to get a login name. If you're worried about privacy, having a login actually gives you more privacy, not less, because the login name doesn't have to be connected in any way to your real-world identity and (unlike logged-out edits) edits made using it cannot be traced to your IP address by most other editors. —David Eppstein (talk) 07:48, 25 September 2021 (UTC)

Oct 2021

I would like advice on the title of the article

See Talk:Ohsawa–Takegoshi theorem. thanks!--SilverMatsu (talk) 03:56, 2 October 2021 (UTC)

done!--SilverMatsu (talk) 06:11, 2 October 2021 (UTC)

Edits by User:Darcourse

User:Darcourse is a long-time editor of mathematics articles. Recently I had the bad experience of checking a chunk of their edits at Derangement. As you can see in the article history, in my view their changes made the article worse in a wide variety of ways, and I essentially undid all of them. I have serious qualms about the quality of their edits to other articles, but limited time and patience to check them. While I wouldn't recommend blanket reversion, I would encourage other editors to keep an eye on any edits from Darcourse that touch articles of interest or importance. --JBL (talk) 11:06, 5 October 2021 (UTC)

Squarefree

Is it Square-free integer or Square-free number? The page is being renamed and moved. Bubba73 ^{You talkin' to me?} 02:17, 25 September 2021 (UTC)

Square-free number sounds better to my ears, and most articles on special classes of integers are named "Something number" (example: Fibonacci number not Fibonacci integer), but square-free integer has about a 5-to-1 advantage in Google Scholar hits, so it seems to be winning WP:COMMONNAME. —David Eppstein (talk) 07:41, 25 September 2021 (UTC)

I did this move mainly for reverting a previous move that was done without any discussion.

Here are the hits that I have found in Google scholar and Google: In Google scholar, 1,100 hits for "square-free number", 542 for "squarefree number", 2,060 for "squarefree integer", and 5,240 for "square-free integer". In Google, 26,700 hits for "square-free number", 10,500 for "squarefree number", 8,780 for "squarefree integer", and 29,200 for "square-free integer". This shows that "square-free integer" is clearly winning in advanced mathematics, and slightly winning in elementary mathematics.

Here is a possible explanation for these results. In the numerous article called "Something number", the word "number" is in fact an abbreviation of "natural number", that is, the concept does not include negative integers. On the other hand, when negative integers are included and/or when confusion with non-integer numbers is possible, "integer" is generally preferred, such as in coprime integers and integers modulo n. Here, "square-free" applies to negative integers, but not to general real numbers (the concept can be extended to rational numbers). So the title "square-free number" may confuse some readers.

However, these are a posteriori explanations. The main reason of my move is to revert a move done without discussion. D.Lazard (talk) 09:10, 25 September 2021 (UTC)

I agree that reverting a move done without discussion is appropriate. Perhaps in elementary number theory, where "number" is sometimes used as a synonym of integer (or positive integer), it is natural to call them "square-free numbers", but my feeling is that for a broader readership, the more precise term "square-free integer" is better. Ebony Jackson (talk) 00:59, 2 October 2021 (UTC)

If it is square-free then it is obviously not a general real number. Bubba73 ^{You talkin' to me?} 23:47, 3 October 2021 (UTC)

I would support Square-free number as less technical: the concept is understandable by people young enough to be uncomfortable with the technical language "integer", and there is no realistic possibility of confusion with some other concept (any more than there is with "number theory"). (Also obviously the reversion was appropriate!) --JBL (talk) 11:08, 5 October 2021 (UTC)

Volume of an N-ball new edits

Would someone from the Mathematics project please have a look at the last few days of edits to Volume of an n-ball? Guswen has made a number of changes, including a negative-dimension recurrence relation, that I am quite skeptical of the utility of. - Parejkoj (talk) 17:21, 6 October 2021 (UTC)

I have tagged the whole section Volume of an n-ball#Recursions as possible WP:OR and not sourced. I suggest to remove the whole section as I do not see any encyclopedic value of giving complicated recursion formulas when one has rather simple closed form formulas. D.Lazard (talk) 18:02, 6 October 2021 (UTC)

Agree the artcle is a mess and needs a bit of control. And the proofs are of little interest, perhaps just keep one short one. NadVolum (talk) 22:51, 8 October 2021 (UTC)

Shuffle symbol ш

The symbol of the shuffle product is the Cyrillic letter ш (sha), and should be implemented in latex as \sha. This is lacking in our implementation. This leads, in our articles, to have awful formulas in raw html, and, in formulas that must be in latex, to use a non standard synbol such as $\omega$ (see Tensor product § Coproduct).

Please, can somebody (who knows how to proceed) ask for fixing this issue. D.Lazard (talk) 13:10, 6 October 2021 (UTC)

I think that might be the Phabricator lot referenced in the box on the top right of my bug about #Messed up math display above NadVolum (talk) 23:00, 8 October 2021 (UTC)

Messed up math display

Tracked in Phabricator
Task T292350

A few formulae in De Moivre's formula are displayed wrong for me, for instance

${\begin{aligned}\sin nx&=\sum _{k=0}^{n}{\binom {n}{k}}(\cos x)^{k}\,(\sin x)^{n-k}\,\sin {\frac {(n-k)\pi }{2}}\\\cos nx&=\sum _{k=0}^{n}{\binom {n}{k}}(\cos x)^{k}\,(\sin x)^{n-k}\,\cos {\frac {(n-k)\pi }{2}}.\end{aligned}}$

I'm using Chrome on Windows 10.

It looks like the SVG produced is fine - but when it is shrunk some of the lines disappear.

If I use Wikipedia to display that as a thumbnail the formula is fine even though it is much smaller! If however that SVG is downloaded and then displayed by itself in Chrome it is messed up.

I guess the problem is in Chrome since Wikipedia can shrink it nicely but should I pass this to someome here or any idea of where or how to report it?

NadVolum (talk) 15:31, 4 October 2021 (UTC)

I think this is an upstream bug in chrome. The SVG is correct, but chrome does not always render it correctly. This was discusses a year or so back on WP:VPT and there may be a ticket about it. --Salix alba (talk): 19:15, 4 October 2021 (UTC)

I'd have never known ho to report it! Thanks. The Google Chrome version I'm using is Version 94.0.4606.71 (Official Build) (64-bit). NadVolum (talk) 16:24, 5 October 2021 (UTC)

I managed to log in there and I uploaded a screen capture of the formulae as I see them too. NadVolum (talk) 16:49, 5 October 2021 (UTC)

I've found the Village pump discussion Wikipedia:Village pump (technical)/Archive 186#bug in chrome causes "math" tag to display incorrectly. This is T269222 and the chromium bug is 1159852.--Salix alba (talk): 12:33, 9 October 2021 (UTC)

List of perfect numbers and Mersenne prime#List of known Mersenne primes

Hi,

I was wondering if these two tables should be merged into one list article in some way -- after all, all known perfect numbers correspond to Mersenne primes and vice versa, and several columns are exactly the same between the two articles outside of the first few rows (rank, p, discovered, discoverer). My only concern is that the table could become too wide, but that could be rectified by shortening the number of digits shown on the big ones (don't think we necessarily need both the first and last 12 digits of every one..) Thoughts? (If there's consensus, I can start writing it myself.) Thanks, eviolite (talk) 15:26, 6 October 2021 (UTC)

I can see your point okay, and wouldn't lose too much sleep if someone did as you say. But I think it probably is better off as it is at the moment. It isn't as though those tables are going to grow at a fast rate and they're not too big and they work fine as they are. No point fixing it if it ain't broke. NadVolum (talk) 22:57, 8 October 2021 (UTC)

M(57885161) has just been verified! I wonder if I say something similar about some other table the same thing will happen ;-) NadVolum (talk) 20:47, 10 October 2021 (UTC)

I was actually checking that the other day since I was expanding List of perfect numbers -- it was supposed to have been done in September, but I had to settle for a "close to".. (Also, re the original question, it was honestly out of a bit of selfishness(?) as I wanted to try and get the article to featured list status, and it would probably be easier to include more context if it had both, especially with the discovered column (which de facto is just the Mersenne prime discoverers since Euclid). I do understand if it would make it actively worse/more complicated though.) eviolite (talk) 21:21, 10 October 2021 (UTC)

Welp @NadVolum: I've gone and boldly started working on one in my sandbox (possibly out of sleep deprivation): see User:Eviolite/sandbox2 - I still need to find and place all the refs/notes in the table properly, but what do you think of it so far? Like I said I'm hoping to reach WP:FL status (it'll be my first piece of good/featured content, see the criteria here). eviolite (talk) 04:38, 13 October 2021 (UTC)

Boldly is actually doing it! It looks to me like someone else has already done it two days ago. It's better to actually do a few edits to the article rather than a big one elsewhere. You can always revert if an edit made things worse. The only reason for much discussion elsewhere and a proposed change is if there is a lot of controversy. Using Show Preview before publishing if editing source is always a good idea though! NadVolum (talk) 10:06, 13 October 2021 (UTC)

@NadVolum: the reason I use a sandbox is that the way I edit often results in incomplete section/articles/the etc. I'm not sure what you're referring to that happened 2 days ago but you might be looking at my own edits to List of perfect numbers? Thanks, eviolite (talk) 10:34, 13 October 2021 (UTC)

I had a look again and I am rather puzzled. What bits f the aricle are you hoping to change? Is it the introduction and table or the whole article? I'm a bit new to all this but I'd be very much more incremetal about changes. NadVolum (talk) 10:43, 13 October 2021 (UTC)

I am changing the entire article of List of perfect numbers, incorporating info from the list on Mersenne prime. The entirety of that prose up there is just a lede for the table - there is no other part of the article. See the FL criteria that requires this. eviolite (talk) 10:48, 13 October 2021 (UTC)

Cognitively Guided Instruction

So while I was looking at mathematics education articles, I stumbled across the article Cognitively Guided Instruction, which was written in 2007 and has hardly been touched since. All its references are written by a single group of authors. I would welcome input on the question of whether this is a notable thing (studied by multiple groups, subject of sources not written by its inventors) whose article is poor but could be improved, or alternatively whether the current article reflects the best possible sourcing (in which case the article should probably be deleted). (I also left a note at Wikipedia talk:WikiProject Education.) --JBL (talk) 11:10, 13 October 2021 (UTC)

Constructive set theory

Can someone knowledgeable enough take a look at this article, parts of it are written in an unencyclopedic way using phrasing such as "we use" etc. Lavalizard101 (talk) 12:13, 16 October 2021 (UTC)

The word "etc." is doing a lot of work in this comment. Huge numbers of mathematics articles use the first person plural (because that's the norm in mathematics papers), and it doesn't require a mathematics specialist to fix this grammatical issue (though doing so is tedious and would take a while on an article of this length). Personally, it is also really low on my list of things to worry about because it does not impede reader understanding at all. --JBL (talk) 12:21, 16 October 2021 (UTC)

There is nothing "unencyclopedic" about standard mathematical style. MOS:WE explicitly says “some such forms [of first-person writing] are acceptable in certain figurative uses. For example: [...] The author's we found in scientific writing, though rephrasing to use passive voice may be preferable.” –jacobolus (t) 12:34, 16 October 2021 (UTC)

However, "we" is often confusing, as the reader cannot know whether "we" refers to the editor of the article, to the author of the source, to Wikipedia, or to the mathematical community. This is specially confusing in sentences such that "we define (or we denote) this as that". Does the reader should understand that it is a definition/notation that is specific to the article, or a standard definition/notation, or a common but nonstandard definition/notation? This important encyclopedic information is often lacking in articles that use "we". D.Lazard (talk) 13:11, 16 October 2021 (UTC)

Calculus education, etc.

Currently, calculus education, geometry education, and algebra education are all redlinks. I'm not sure what article (if any) those should redirect to. User:力 (power~enwiki, π, ν) 21:51, 12 October 2021 (UTC)

None. Why do you think they should point anywhere? There not even used in any article. NadVolum (talk) 22:40, 12 October 2021 (UTC)

I think calculus reform is a notable topic, to which calculus education could point, but we don't appear to have an article on it. I'm not convinced that the other two make notable subtopics of geometry and algebra more generally. —David Eppstein (talk) 23:16, 12 October 2021 (UTC)

I imagine there's a robust literature about all of these things, but if so it's generated & consumed by people who study education, not people who study mathematics. I mean, people have been arguing about geometry education for 2000+ years. --JBL (talk) 23:44, 12 October 2021 (UTC)

I think there is (real) analytic education as a article similar to calculus education.--SilverMatsu (talk) 00:41, 13 October 2021 (UTC)

@力: Looking around a bit more, Mathematics education would be a suitable redirect target for all of these. --JBL (talk) 01:03, 13 October 2021 (UTC)

There is no benefit in turning any of these unused and un-asked-for red links into redirects. But if someone wanted to do the research about the history and/or practice of the education of any of these subjects, a worthwhile article could plausibly be written about any of them. Mathematics education would not be a suitable redirect target in its current form: it doesn’t specifically discuss any of these. –jacobolus (t) 16:24, 13 October 2021 (UTC)

it doesn’t specifically discuss any of these That's ... not true. For example, a person looking for information about geometry education would find at Mathematics education some historical information, and would learn that geometry is taught both as an example of practical mathematics and as an example of an axiomatic system and a model for deductive reasoning, that it is conventionally introduced after arithmetic and alongside elementary algebra, and that in the US there is typically a year-long course focusing on geometry. (Is this enough material for a stand-alone article, or even a complete section? No, of course not. But is it enough to support a redirect? Sure.) --JBL (talk) 17:40, 13 October 2021 (UTC)

I saw Mathematics education, but agree with jacobolus that it isn't currently a good redirect target. That said, it is used as one. While Precalculus has an article, Algebra I does not - that link currently goes to mathematics education but should probably retarget to Elementary algebra. There is certainly enough material published to have a section somewhere on each; I may just add those sections to Mathematics education. Is the quadratic equation taught before ring theory, and why? Should elementary algebra classes be taught to 11 year olds or 14 year olds? When did "algebra" first become part of the curriculum at schools like Eton College? These questions and more are surely discussed and of interest to encyclopedia readers. User:力 (power~enwiki, π, ν) 17:48, 13 October 2021 (UTC)

Jacobolus's point seems correct, but I tend to agree with JayBeeEll's suggestion. see Wikipedia:Redirects are cheap. However, instead of redirecting the talk page, we recommend using "Template:WikiProject Mathematics" to create a place for discussion in case they want to create the stand-alone articles.--SilverMatsu (talk) 00:27, 14 October 2021 (UTC)

That's ... not true. – Two or three scattered throw-away sentences is not a meaningful amount of content for someone curious about “geometry education” or “algebra education”. The math education article currently does not cover these in a meaningful way, and creating redirects for these would not provide value to Wikipedia. If you want to add a separate section with a few paragraphs summarizing one of these subjects, go right ahead; at that point, you could make a redirect. Alternately, go write a whole article at one of those pages. Even a few-paragraph stub would be much more useful than a redirect. Otherwise, discussing more here is a waste of time. –jacobolus (t) 01:29, 14 October 2021 (UTC)

I have no quibble with the claim that the coverage of these more specific topics in that more general article is very light (as you can tell by reading my comment, viz. Is this enough material for a stand-alone article, or even a complete section? No, of course not.). I only have a quibble with the particular (false) claim it doesn’t specifically discuss any of these. The reason that I object to that false claim is that it implies, incorrectly, that I didn't check whether geometry education etc. is mentioned in Mathematics education; whereas I did check to confirm that each of these topics is specifically mentioned there. I agree that further discussion of this point would be a waste of time, and I suggest that in the future you adopt a less aggressive tone (and particularly avoid saying false things aggressively) in order to avoid such pointless wastes of time. --JBL (talk) 20:18, 15 October 2021 (UTC)

@力: I suggest not changing the redirect target for Algebra I. Algebra I is used in some mathematics lectures (course) and textbook titles. (e.g. Michael Artin. 18.701 Algebra I. Fall 2010. Massachusetts Institute of Technology: MIT OpenCourseWare, N. Bourbaki Algebra I: Chapters 1-3 at Google Books.) But I agree that "Algebra I" can mean Elementary algebra.--SilverMatsu (talk) 00:54, 17 October 2021 (UTC)

list

• Calculus education note; red link
• Talk:Calculus education note; red link
• Geometry education note; red link
• Talk:Geometry education note; red link
• Algebra education note; redirect to Category:Algebra education
• Talk:Algebra education note; red link

about Coxeter–Dynkin diagram

see Talk:Coxeter–Dynkin_diagram#store_into_wikidata.

I would like to store Coxeter–Dynkin diagram into wikidata, but now Coxeter–Dynkin diagram is display by multiple images e.g. . wikidata doesn't support. (see d:Wikidata:Project_chat#datatype_for_en:Coxeter–Dynkin_diagram?)-- Nanachi🐰Fruit Tea☕（宇帆·☎️·☘️） 08:57, 2 October 2021 (UTC)

• @Tomruen:. -- Nanachi🐰Fruit Tea☕（宇帆·☎️·☘️） 13:28, 10 October 2021 (UTC)

I don't know about how wikidata works. Tom Ruen (talk) 17:10, 10 October 2021 (UTC)

@Tomruen: Is there any standard way of representing Coxeter–Dynkin diagrams as strings? -- Nanachi🐰Fruit Tea☕（宇帆·☎️·☘️） 06:54, 11 October 2021 (UTC)

I don't know what the question means. Ascii strings? Like x4o3o for ?

Yes, Ascii strings. Does x4o3o a standard way of representing Coxeter–Dynkin diagrams?-- Nanachi🐰Fruit Tea☕（宇帆·☎️·☘️） 09:04, 11 October 2021 (UTC)

There are a bunch of not particularly compelling attempts in Coxeter–Dynkin_diagram#Affine_Coxeter_groups to extend the natural notation for linear diagrams to more complicated graphs. (If one restricts to the finite case, life is not so bad because there is only ever a single branch-point.) Also of course there is the Cartan matrix. --JBL (talk) 11:04, 11 October 2021 (UTC)

Richard Klitzing lists all the uniform polytopes with a linearized CD, like polyhedra [11], including loops (common on star forms, w/rational branch orders), like *a at the end for a cyclic diagram returning to first node. Its a bit hard to read, but I'd recommend copying it, if you needed say an input format to generate solutions in a program. Richard also lists incidence matrices which count how many elements in each position of a Kaleidoscopic construction, grouped by element size, Tom Ruen (talk) 11:01, 18 October 2021 (UTC)

Example , truncated cuboctahedron, [12], 1 type of vertex, 3 types of edges, and 3 types of faces: (Note: is an edge, and = = square)

x3x4x

. . . | 48 |  1  1  1 | 1  1 1
------+----+----------+-------
x . . |  2 | 24  *  * | 1  1 0
. x . |  2 |  * 24  * | 1  0 1
. . x |  2 |  *  * 24 | 0  1 1
------+----+----------+-------
x3x . |  6 |  3  3  0 | 8  * *
x . x |  4 |  2  0  2 | * 12 *
. x4x |  8 |  0  4  4 | *  * 6

• Thanks for your answer. But I still have a question. Can Coxeter diagram be rotation, deformation or reflection? I have observed that the wikipedia article Order-4 dodecahedral honeycomb writes but the diagram given by Richard Klitzing's website is o3o3o *b5x [13]. Does the description structures of (x5o3o *b3o) and (o3o3o *b5x) equal? I have the same question in {{Octahedral truncations}}: for example, Coxeter diagram of Cuboctahedron are , does it same with ? If it can be rotation, deformation or reflection, does it mean that and represent the same structure?-- Nanachi🐰Fruit Tea☕（宇帆·☎️·☘️） 15:20, 19 October 2021 (UTC)

  YES, A Coxeter-Dynkin diagram is just a graph, and node position is only aesthetic. Each node is a hyperplane of reflection, each branch order p represents a 180°/p dihedral angle between hyperplanes. A rank n diagram has n nodes and n(n-1)/2 branches, but usually right angles are suppressed (branch order 2) since orthogonal mirrors don't interact. For example, this graph shows diagrams and fundamental simplex domains for 3D space groups File:Coxeter-Dynkin_3-space_groups.png, red edges are orthogonal, so not in the diagram. Those three diagrams are related by doublings. [4,3,4] becomes [4,3^(1,1)]] with one mirror removed, and becomes [3^[4]] with another mirror removed. Tom Ruen (talk) 16:13, 19 October 2021 (UTC)

Wikipedia:Articles for deletion/List of Fields Medal winners by university affiliation

This deletion discussion may be of interest to the community here. XOR'easter (talk) 22:03, 21 October 2021 (UTC)

Mathbot is making progress towards coming back

User:Mathbot, the bot which has been updating Wikipedia:WikiProject_Mathematics/List_of_mathematics_articles for some years now has been offline for some weeks now because changes on the Wikipedia server broke it. I am trying to move to the better-supported Pywikibot framework to avoid such issues in the future, but that is taking time.

Note sure if its work is still helpful. It used to be that mathematics editors would keep track of User:Mathbot/Changes to mathlists to see what new articles were added. Anyhow, today it made a big update to these lists. It won't be fully online for another week or two as there are still some more things to fix and test. Oleg Alexandrov (talk) 03:06, 24 October 2021 (UTC)

Lunar arithmetic

See Lunar arithmetic. Does this article meet Wikipedia:Notability ?--SilverMatsu (talk) 07:16, 24 October 2021 (UTC)

Regular Platonic solid polyhedra

Is there something that I'm missing that distinguishes the two, or do we really have two different articles (both vital!) on the same topic, Platonic solid and regular polyhedron? —David Eppstein (talk) 07:44, 22 October 2021 (UTC)

According to the articles there are 9 regular polyhedra but only 5 platonic solids, so they are not exactly synonymous — Martin (MSGJ · talk) 07:50, 22 October 2021 (UTC)

Platonic solids are convex, but there exist four regular star polyhedra, too. I agree, there is a good bit of overlap between the two articles.--{{u|Mark viking}} {Talk} 08:38, 22 October 2021 (UTC)

Maybe the second one should be retitled "regular star polyhedra" to avoid overlap? Never mind, this is not a particularly good suggestion given the existing content. --JBL (talk) 11:38, 22 October 2021 (UTC)

Having both seems fine. These are distinct concepts, albeit with substantial overlap. The regular polyhedron article redirects readers to Platonic solid for more information about those specifically. –jacobolus (t) 19:10, 22 October 2021 (UTC)

Maybe regular polyhedron could be a set index article? We don't need to have three articles on Platonic Solid, Kepler–Poinsot polyhedron, and Platonic Solid $\cup$ Kepler–Poinsot polyhedron, so having a much shorter regular polyhedron article that points to those other more specific topics and to other related notions seems reasonable. —David Eppstein (talk) 19:22, 22 October 2021 (UTC)

Is there something about these articles that is unclear? Or you think the maintenance burden of having some overlapping material is too high? Or ...? I don’t really understand what the problem is. –jacobolus (t) 02:51, 23 October 2021 (UTC) Update: I would consider regular polyhedron to be somewhat of a Wikipedia:General overview article. –jacobolus (t) 03:34, 23 October 2021 (UTC)

Our whole area of polyhedron articles is a disaster zone of every article about some polyhedron or some kind of polyhedron having huge off-topic sections of image galleries and calculation-cruft about every other kind of polyhedron. I would like everything to be more focused. But it seems there is not so much interest in that kind of effort. —David Eppstein (talk) 02:01, 24 October 2021 (UTC)

Just to make sure I have a correct grasp on the situation, it appears that we have at least the following things:

• An article Platonic solid, on the five regular convex polyhedra
• An article Kepler–Poinsot polyhedra, on the four regular star polyhedra
• A redirect Regular polyhedral compound, which points to a section of Polyhedral compound,
• An article Regular polyhedron, which has sections about all of those things, as well as some other generalizations (though oddly not the natural generalization to higher dimensions, as far as I see), and
• An article Regular polytope, which seems to include content on all of the cases above (maybe not compounds).

The level of redundancy here is really extreme; for example, there are 4 separate but overlapping detailed history sections among these articles. Is there any content in the article Regular polyhedron that isn't already contained in one of the other articles? --JBL (talk) 01:17, 25 October 2021 (UTC)

See also Regular map (graph theory) (abstract versions of the same things on non-sphere 2-manifolds), Uniform polyhedron, Regular skew polyhedron, and significant material on regular instances in Abstract polytope and Projective polyhedron, at least. —David Eppstein (talk) 06:23, 25 October 2021 (UTC)

List of mathematical series

I imagine that a page like List of mathematical series naturally tends to accumulate everybody's favorite series. Should we put some thought into what belongs and what can be trimmed? XOR'easter (talk) 01:26, 24 October 2021 (UTC)

I found Series expansion as a similar article.--SilverMatsu (talk) 02:49, 27 October 2021 (UTC)

@XOR'easter: My first hunch is to restrict such a list to WP-notable series, either with existing standalone WP articles or covered in existing WP articles. — MarkH₂₁^talk 15:11, 27 October 2021 (UTC)

I agree. This must apply to every list article (including glossaries): each entry must be linked or sourced. Moreover, links are often not sufficient, as this must be sourced in the target article. D.Lazard (talk) 16:10, 27 October 2021 (UTC)

Wikipedia also functions as an almanac, so an article akin to the tables of series and integrals found in textbooks from the mid-20th century seems reasonable. I don't know how or whether we should require sourcing that the various entries are in fact often on that type of list. We certainly don't want everyone's favorite series; there must be some inclusion criteria. But I think "every entry must have a stand-alone article" is too much for that criterion. User:力 (power~enwiki, π, ν) 16:13, 27 October 2021 (UTC)

Volume of an n-ball

The continuous/negative-dimensional crank Guswen / Gus~plwiki is back at Volume of an n-ball; see recent edit history there as well as User talk:David Eppstein#Domain of applicability for n-ball volume and surface formulas. More eyes on that page would be helpful. —David Eppstein (talk) 19:26, 27 October 2021 (UTC)

Nov 2021

Wikipedia talk:WikiProject Mathematics/Archive/2021/Nov

Dec 2021

Wikipedia talk:WikiProject Mathematics/Archive/2021/Dec