proposition: Lemma abgr_epi_cokernel_isCokernel_comm {A B C : abgr} (f : abgr_category⟦A, B⟧) (isE : isEpi f) (h : abgr_category⟦A, C⟧) (H : KernelArrow (abgr_Kernel f) · h = ZeroArrow abgr_Zero (abgr_Kernel f) C) : f · abgr_epi_cokernel_out_monoidfun f isE h H = h.
proof: Proof. use total2_paths_f. - use funextfun. intros x. use pathsinv0. exact (pr2 (iscontrpr1 (abgr_epi_CokernelOut_iscontr f isE h H (pr1 f x))) (@make_hfiber _ _ (pr1 f) (pr1 f x) x (idpath _))). - use proofirrelevance. use isapropismonoidfun. Qed.
imports: UniMath.Foundations.PartD UniMath.Foundations.Propositions UniMath.Foundations.Sets UniMath.Foundations.UnivalenceAxiom UniMath.Algebra.BinaryOperations UniMath.Algebra.Groups UniMath.Algebra.Monoids UniMath.NumberSystems.Integers UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.Core.Univalence UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.Monics UniMath.CategoryTheory.Epis UniMath.CategoryTheory.CategoriesWithBinOps UniMath.CategoryTheory.PrecategoriesWithAbgrops UniMath.CategoryTheory.PreAdditive UniMath.CategoryTheory.Additive UniMath.CategoryTheory.Abelian UniMath.CategoryTheory.Limits.Zero UniMath.CategoryTheory.Limits.BinProducts UniMath.CategoryTheory.Limits.BinCoproducts UniMath.CategoryTheory.Limits.Equalizers UniMath.CategoryTheory.Limits.Coequalizers UniMath.CategoryTheory.Limits.Kernels UniMath.CategoryTheory.Limits.Cokernels UniMath.CategoryTheory.Limits.BinDirectSums