Commit 2024-04-16 10:25 d83efb31
View on Github →refactor(CategoryTheory): more general form of the characterisation of condensed sets as sheaves on Stonean
(#11518)
Given a fully faithful functor F : C ⥤ D
into a precoherent category, which preserves and reflects finite effective epi families, and satisfies the property F.EffectivelyEnough
(meaning that to every object in C
there is an effective epi from an object in the image of F
), the categories of coherent sheaves on C
and D
are equivalent.
We give the corresonding result for the regular topology as well.
We use this general setup to refactor the characterisation of condensed sets as sheaves on Stonean
; indeed, the inclusion functor to CompHaus
satisfies Functor.EffectivelyEnough
because the Stonean spaces are the projective objects in CompHaus
, which has enough projectives and every epimorphism in CompHaus
is effective.