fact: Definition is_z_isomorphism_mor {C : precategory_data} {a b : C} {f : a --> b} (I : is_z_isomorphism f) : b --> a := pr1 I.
imports: UniMath.Foundations.PartA UniMath.Foundations.Propositions UniMath.Foundations.Sets UniMath.MoreFoundations.Tactics UniMath.CategoryTheory.Core.Categories