Lemma idtoiso_fiber_disp {C} {D : disp_cat C} {x : C} {xx xx' : D x} (ee : xx = xx') : z_iso_disp (identity_z_iso x) xx xx'. Proof. exact (idtoiso_disp (idpath _) ee). Defined.
Require Import UniMath.Foundations.Sets. Require Import UniMath.MoreFoundations.PartA. Require Import UniMath.CategoryTheory.Core.Categories. Require Import UniMath.CategoryTheory.Core.Isos. Require Import UniMath.CategoryTheory.Core.Univalence. Require Import UniMath.CategoryTheory.DisplayedCats.Core.