fact: Definition Epi_comp {x y z : C} (E1 : Epi x y) (E2 : Epi y z) : Epi x z := tpair _ (E1 · E2) (isEpi_comp E1 E2 (pr2 E1) (pr2 E2)).
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