proposition: Lemma isapropisEpi {y z : C} (f : y --> z) : isaprop (isEpi f).
proof: Proof. apply impred_isaprop; intros t. apply impred_isaprop; intros g. apply impred_isaprop; intros h. apply impred_isaprop; intros H. apply hs. Qed.
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