proposition: Lemma z_iso_eq {C : category} {a b : C} (i i' : z_iso a b) (e : z_iso_mor i = z_iso_mor i') : i = i'.
proof: Proof. use total2_paths_f. - exact e. - use proofirrelevance. apply isaprop_is_z_isomorphism. Qed.
imports: UniMath.Foundations.PartA UniMath.Foundations.Propositions UniMath.Foundations.Sets UniMath.MoreFoundations.Tactics UniMath.CategoryTheory.Core.Categories