@ocaramello Uh, I see! Indeed, you/your slides never refer to objects. I mistakenly went for a subcategory, which includes identities, hence objects, ...

@jens-hemelaer thanks!

Actually, I thought I understood the distinction between rigid and 'admitting smallest coverings' for posets, but now I don't anymore. If I spell out ...

Thanks, it's been really helpful! Unfortunately my algebras are non-atomic, so the mystery remains. I believe then sheafification is not going to prod...

@ocaramello Ok thanks for the clarification. Let me see if I got it right: you're saying, for Cauchy complete , rigid topologies correspond exactl...

Thanks to everyone for your answers! Sorry to have let so much time pass since I posted this: it's kind of a side-project and I didn't return on it un...

I know almost nothing about categorical model theory but isn't trading a function for a a form of 'de-Skolemization'? Skolemization is the inverse pr...

Thanks @john-dee, that should be relevant to another question of mine that I didn't communicate here.

Good catch! It's a typo (sigh, also ! and * should be superscripts, not subscripts), the formula should read:Same for the right Kan extension. Also ...

Good idea, I didn't think of using the co/end formulas. Checking them, I get what I ansatzed in my original post 🙂

Here are the notes I was referring to:

I'm definitely enamoured with this point of view. And I also think is the instance of a much more common problem solving technique. I've tried to expl...