Re: size_question

Le mardi 28 juin 2011 19:39:10, vous avez écrit :

This is a naive question on non naive foundations.

Consider the inclusion S_f C S of finite sets in sets.

Is the category S_f closed under finite limits and at the same time small ?

For example, there are a proper class of singletons, all finite. Thus a proper class of empty limits.

This is the definition of quasi-small, not small: a set of isomorphism classes ? The category of finite sets is quasi-small, not small. And we need the axiom of choice for that, as for many things in category theory. pg. [For admin and other information see: http://www.mta.ca/~cat-dist/ ]