Talk:Pregeometry (model theory)

What kind of closure?[edit]

Should the closure link point to Closure (mathematics) or Closure (topology)? —Keenan Pepper 00:50, 29 August 2006 (UTC)[reply]

Closure (mathematics) is correct, since the various notions of closure used in model theory (definable closure, algebraic closure, bounded closure, closure w.r.t. forking on the realisations of a regular type) are all examples of closure operators. Closure (topology) is another example which does not overlap with the model theoretic notions, except in very special cases. Algebraic closure in algebra is an important special case of one of the model theoretic notions. —Hans Adler 22:05, 8 November 2007 (UTC)[reply]

Obsolete article?[edit]

I am a matroid theorist. As far as I know, the term "pregeometry" has no meaning except as a shorthand for "combinatorial pregeometry". The term "combinatorial pregeometry" is identical to "matroid". I never heard of using this term for a special kind of infinite matroid. I hope it isn't true, since there is no reason to use such a vague term for any kind of matroid.

As for the physics, unless someone knows that Wheeler intended to refer to matroids, AND that it led to something in physics, I think the connection of matroids with physics is spurious.

Thus, there is no reason for this article, and it should be merged into Matroid.

I may have my facts wrong, but since I studied with Rota, I'm sure I'm not entirely wrong! Any comments? Factual, please. Zaslav (talk) 01:31, 4 February 2008 (UTC)[reply]

Update: Pregeometry has an entirely different usage in physics. Thus, a disambiguation page was needed. Pregeometry in model theory seems to be a specialization of the meaning of "combinatorial pregeometry" in matroid theory, where it simply means "matroid". Please, model theorists, help out here! Zaslav (talk) 07:22, 4 February 2008 (UTC)[reply]