Definition pr1_idtoiso_concat {C : category} {x y z : C} (f : x = y) (g : y = z) : pr1 (idtoiso (f @ g)) = pr1 (idtoiso f) · pr1 (idtoiso g).
Require Import UniMath.Foundations.PartA. Require Import UniMath.Foundations.Sets. Require Import UniMath.MoreFoundations.PartA. Require Import UniMath.MoreFoundations.Tactics. Require Import UniMath.CategoryTheory.Core.Categories. Require Import UniMath.CategoryTheory.Core.Isos.