Lemma yoneda_unit_is_nat_trans : is_nat_trans (functor_identity (hom_data (representable B_is_univalent_2_1 X) F)) (yoneda_to_presheaf ∙ presheaf_to_yoneda) yoneda_unit_component_mod. Proof. intros η₁ η₂ m. apply modification_eq. intros Z. apply nat_trans_eq. { apply homset_property. } intros g ; cbn in g. cbn. unfold yoneda_unit_component_mod_component_nat_component, yoneda_to_presheaf_data_ob, presheaf_to_yoneda_mor_modification_nat_trans_data, yoneda_to_presheaf_data_mor. refine (!_). etrans. { rewrite <- assoc. apply maponpaths. exact (!(nat_trans_eq_pointwise (mod_inv_naturality_of m X Z g) (id₁ X))). } simpl. rewrite !assoc. apply maponpaths_2. exact (pr2 ((m : modification _ _) Z) _ _ (rinvunitor g)). Qed.
Require Import UniMath.Foundations.All. Require Import UniMath.MoreFoundations.All. Require Import UniMath.CategoryTheory.Core.Categories. Require Import UniMath.CategoryTheory.Core.Univalence. Require Import UniMath.CategoryTheory.Core.Isos. Require Import UniMath.CategoryTheory.Core.Functors. Require Import UniMath.CategoryTheory.Core.NaturalTransformations. Require Import UniMath.Bicategories.Core.Bicat. Import Bicat.Notations. Require Import UniMath.Bicategories.Core.BicategoryLaws. Require Import UniMath.Bicategories.Core.Examples.OpMorBicat. Require Import UniMath.Bicategories.Core.Examples.BicatOfUnivCats. Require Import UniMath.Bicategories.Core.EquivToAdjequiv. Require Import UniMath.Bicategories.Core.Unitors. Require Import UniMath.Bicategories.Morphisms.Adjunctions. Require Import UniMath.Bicategories.Morphisms.Properties. Require Import UniMath.Bicategories.Core.Invertible_2cells. Require Import UniMath.Bicategories.Core.Univalence. Require Import UniMath.Bicategories.Core.UnivalenceOp. Require Import UniMath.Bicategories.PseudoFunctors.Display.PseudoFunctorBicat. Require Import UniMath.Bicategories.PseudoFunctors.PseudoFunctor. Import PseudoFunctor.Notations. Require Import UniMath.Bicategories.PseudoFunctors.Properties. Require Import UniMath.Bicategories.Transformations.PseudoTransformation. Require Import UniMath.Bicategories.Modifications.Modification. Require Import UniMath.Bicategories.PseudoFunctors.Yoneda. Require Import UniMath.Bicategories.PseudoFunctors.Representable. Require Import UniMath.Bicategories.Core.Examples.Image. Require Import UniMath.Bicategories.PseudoFunctors.Examples.CorestrictImage.