Lemma fourth_iso_nat_in_x (F : PreShv C) : is_nat_trans (pr1 (Fun3 F)) _ (λ x, fourth_iso_on_sets F x). Proof. intros X Y f. use (is_natural_yoneda_iso _ _ _ _ (BinProduct_of_functors_mor _ _ PC _ _ _ _ _)). Qed.
Require Import UniMath.MoreFoundations.All. Require Import UniMath.CategoryTheory.Core.Categories. Require Import UniMath.CategoryTheory.Core.Functors. Require Import UniMath.CategoryTheory.Core.Isos. Require Import UniMath.CategoryTheory.Core.NaturalTransformations. Require Import UniMath.CategoryTheory.Limits.BinProducts. Require Import UniMath.CategoryTheory.exponentials. Require Import UniMath.CategoryTheory.whiskering. Require Import UniMath.CategoryTheory.opp_precat. Require Import UniMath.CategoryTheory.FunctorCategory. Require Import UniMath.CategoryTheory.RightKanExtension. Require Import UniMath.CategoryTheory.Adjunctions.Core. Require Import UniMath.CategoryTheory.yoneda. Require Import UniMath.CategoryTheory.YonedaBinproducts. Require Import UniMath.CategoryTheory.Categories.HSET.Core. Require Import UniMath.CategoryTheory.Categories.HSET.Limits. Require Import UniMath.CategoryTheory.Categories.HSET.Structures. Require Import UniMath.CategoryTheory.Categories.HSET.MonoEpiIso. Require Import UniMath.CategoryTheory.Limits.Graphs.Limits. Require Import UniMath.CategoryTheory.Presheaf.