Definition disp_nat_z_iso_comp {α: nat_z_iso F G} {α': nat_z_iso G H} (β: disp_nat_z_iso DF DG α) (β': disp_nat_z_iso DG DH α') : disp_nat_z_iso DF DH (nat_z_iso_comp α α') . Proof. exists (disp_nat_trans_comp β β'). intros c d. exists (disp_nat_trans_comp (disp_nat_z_iso_inv β') (disp_nat_z_iso_inv β) c d). apply disp_nat_trans_comp_inv. Defined.
Require Import UniMath.Foundations.Sets. Require Import UniMath.MoreFoundations.PartA. Require Import UniMath.CategoryTheory.Core.Categories. Require Import UniMath.CategoryTheory.Core.Functors. Require Import UniMath.CategoryTheory.Core.NaturalTransformations. Require Import UniMath.CategoryTheory.Core.Isos. Require Import UniMath.CategoryTheory.whiskering. Require Import UniMath.CategoryTheory.FunctorCategory. Require Import UniMath.CategoryTheory.DisplayedCats.Core. Require Import UniMath.CategoryTheory.DisplayedCats.Functors. Require Import UniMath.CategoryTheory.DisplayedCats.Isos.