Thanks, I didn't know this -- I was actually wondering whether such a result exists in the literature!

Nice comments and references! tl;dr Is there a general theorem about geometric constructions or is it more of a slogan? I think the reason I alway...

I saw this post only now, but thanks for taking the initiative, @jwrigley! I'd like to have something like this after (and in between) the talks the n...

Well, I the intuition is that in any (Grothendieck) topos , you can divide out an equivalence relation to get an epimorphism and you can also get ba...

One of my favorite geometric theories to play around with is the "theory of a surjection": take two sorts and , a unary function symbol and a single...