Documentation

Mathlib.Condensed.Epi

Epimorphisms of condensed objects #

This file characterises epimorphisms of condensed sets and condensed R-modules for any ring R, as those morphisms which are objectwise surjective on Stonean (see CondensedSet.epi_iff_surjective_on_stonean and CondensedMod.epi_iff_surjective_on_stonean).

theorem CondensedSet.epi_iff_locallySurjective_on_compHaus {X Y : CondensedSet} (f : X โŸถ Y) :
CategoryTheory.Epi f โ†” โˆ€ (S : CompHaus) (y : Y.obj.obj (Opposite.op S)), โˆƒ (S' : CompHaus) (ฯ† : S' โŸถ S) (_ : Function.Surjective โ‡‘(CategoryTheory.ConcreteCategory.hom ฯ†)) (x : X.obj.obj (Opposite.op S')), f.hom.app (Opposite.op S') x = Y.obj.map (Opposite.op ฯ†) y
theorem CondensedMod.epi_iff_locallySurjective_on_compHaus (R : Type (u + 1)) [Ring R] {X Y : CondensedMod R} (f : X โŸถ Y) :
CategoryTheory.Epi f โ†” โˆ€ (S : CompHaus) (y : โ†‘(Y.obj.obj (Opposite.op S))), โˆƒ (S' : CompHaus) (ฯ† : S' โŸถ S) (_ : Function.Surjective โ‡‘(CategoryTheory.ConcreteCategory.hom ฯ†)) (x : โ†‘(X.obj.obj (Opposite.op S'))), (CategoryTheory.ConcreteCategory.hom (f.hom.app (Opposite.op S'))) x = (CategoryTheory.ConcreteCategory.hom (Y.obj.map (Opposite.op ฯ†))) y
theorem CondensedMod.epi_iff_surjective_on_stonean (R : Type (u + 1)) [Ring R] {X Y : CondensedMod R} (f : X โŸถ Y) :
CategoryTheory.Epi f โ†” โˆ€ (S : Stonean), Function.Surjective โ‡‘(CategoryTheory.ConcreteCategory.hom (f.hom.app (Opposite.op S.compHaus)))