This PR defines projective objects, and proves a bunch of properties about them. It also defines set-projective types, and shows that projectivity of propositions + a set-projective dedekind type implies countable choice. This closes #420.
Checklist
Before submitting a merge request, please check the items below:
[x] The imports of new modules have been sorted with support/sort-imports.hs (or nix run --experimental-features nix-command -f . sort-imports).
[x] 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:.
Lavenza
commented
3 months ago
Description
This PR defines projective objects, and proves a bunch of properties about them. It also defines set-projective types, and shows that projectivity of propositions + a set-projective dedekind type implies countable choice. This closes #420.
Checklist
Before submitting a merge request, please check the items below:
support/sort-imports.hs(ornix run --experimental-features nix-command -f . sort-imports).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:.