fact: Definition z_iso_is_z_isomorphism {C : precategory_data} {a b : C} (I : z_iso a b) : is_z_isomorphism I.
imports: UniMath.Foundations.PartA UniMath.Foundations.Propositions UniMath.Foundations.Sets UniMath.MoreFoundations.Tactics UniMath.CategoryTheory.Core.Categories