proposition: Lemma CoequalizerArrowEpi {y z : C} {f g : y --> z} (E : Coequalizer f g ) : Epi _ z E.
proof: Proof. exact (make_Epi C (CoequalizerArrow E) (CoequalizerArrowisEpi E)). Defined.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.Univalence UniMath.CategoryTheory.Epis UniMath.CategoryTheory.Limits.BinCoproducts UniMath.CategoryTheory.Retracts