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Mathlib.CategoryTheory.Sites.Coherent.ReflectsPreregular

Reflecting the property of being preregular #

We prove that given a fully faithful functor F : C ⥤ D, with Preregular D, such that for every object X of D there exists an object W of C with an effective epi π : F.obj W ⟶ X, the category C is Preregular.

theorem CategoryTheory.Functor.reflects_preregular {C : Type u_1} {D : Type u_2} [CategoryTheory.Category.{u_3, u_1} C] [CategoryTheory.Category.{u_4, u_2} D] (F : CategoryTheory.Functor C D) [F.PreservesEffectiveEpis] [F.ReflectsEffectiveEpis] [F.EffectivelyEnough] [CategoryTheory.Preregular D] [F.Full] [F.Faithful] :