proposition: Lemma identity_is_z_iso {C : precategory} (a : ob C) : is_z_isomorphism (identity a).
proof: Proof. exists (identity a). simpl; split; apply id_left. Defined.
imports: UniMath.Foundations.PartA UniMath.Foundations.Propositions UniMath.Foundations.Sets UniMath.MoreFoundations.Tactics UniMath.CategoryTheory.Core.Categories