fact: Definition make_isEpi {x y : C} (f : x --> y) (H : ∏ (z : C) (g h : y --> z), f · g = f · h -> g = h) : isEpi f := H.
imports: UniMath.Foundations.PartD UniMath.Foundations.Propositions UniMath.Foundations.Sets UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.NaturalTransformations UniMath.CategoryTheory.FunctorCategory UniMath.CategoryTheory.Subcategory.Core UniMath.CategoryTheory.Core.Functors