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@4e554c4c 4e554c4c commented Aug 1, 2025

Description

I wanted to introduce total categories (see #489) and some of their properties, in particular their adjoint functor theorem (that any cocontinuous functor from a total category has a right adjoint).

This turned out to be really hard, and I didn't finish it (but I'm still working). In particular, adjoint functor theorems seem to be all about size conditions, and these are a bit tricky when converting from classical texts to the 1lab.

Instead, I explored a lot of concepts, dualized many more, and I thought it'd be best to PR what I have before it gets any more bloated.

Notable (non-dual) additions are:

  • wide pullbacks
  • free objects are colimits
  • diagonal adjoints are (co)limits
  • absolute kans are adjoints
  • all presheaf epis are regular

Checklist

Before submitting a merge request, please check the items below:

  • I've read the contributing guidelines.
  • The imports of new modules have been sorted with support/sort-imports.hs (or nix run --experimental-features nix-command -f . sort-imports).
  • All new code blocks have "agda" as their language.

If your change affects many files without adding substantial content, and
you don't want your name to appear on those pages (for example, treewide
refactorings or reformattings), start the commit message and PR title with chore:.

@4e554c4c 4e554c4c force-pushed the total branch 4 times, most recently from 864e913 to bbbb0ca Compare August 1, 2025 16:19
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Lavenza commented Aug 1, 2025

@4e554c4c 4e554c4c requested a review from plt-amy August 2, 2025 18:36
@4e554c4c 4e554c4c force-pushed the total branch 3 times, most recently from e5cdcc3 to ebe6544 Compare August 24, 2025 14:03
@4e554c4c 4e554c4c requested a review from plt-amy August 24, 2025 14:43
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4e554c4c commented Sep 9, 2025

rebased 😇

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plt-amy commented Sep 20, 2025

theres some conflicts with #568 where you weakened the assumption that various indexing types are sets to them being groupoids while i found a way to just drop the assumption entirely. shouldn't be difficult. i think i might be able to do it?

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thanks @plt-amy! do you think this is ready now?

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bump

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wjhatevber just leave me alone

@plt-amy plt-amy enabled auto-merge (squash) October 29, 2025 20:45
@plt-amy plt-amy merged commit ec9c836 into the1lab:main Oct 29, 2025
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4 participants