proposition: Proposition idtoiso_idpath {C : category} (x : C) : pr1 (idtoiso (idpath x)) = identity x.
proof: Proof. apply idpath. Qed.
imports: UniMath.Foundations.PartA UniMath.Foundations.Sets UniMath.MoreFoundations.PartA UniMath.MoreFoundations.Tactics UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Isos