Definition Y_inhab (b b' : B) (f : b --> b') (a0 : A) (h0 : z_iso (H a0) b) (a0' : A) (h0' : z_iso (H a0') b') : Y f. Proof. set (hfh := h0 · f · inv_from_z_iso h0'). set (l0 := fH^-1 hfh). set (g0 := inv_from_z_iso (k b a0 h0) · #F l0 · k b' a0' h0'). exists g0. apply Y_inhab_proof. Defined.
Require Import UniMath.Foundations.PartD. Require Import UniMath.Foundations.Propositions. Require Import UniMath.Foundations.Sets. Require Import UniMath.MoreFoundations.Tactics. Require Import UniMath.MoreFoundations.Univalence. Require Import UniMath.CategoryTheory.Core.Categories. Require Import UniMath.CategoryTheory.Core.Isos. Require Import UniMath.CategoryTheory.Core.Univalence. Require Import UniMath.CategoryTheory.Core.Functors. Require Import UniMath.CategoryTheory.FunctorCategory. Require Import UniMath.CategoryTheory.whiskering.