Definition all_companions_double_cat_to_verity_double_bicat {C : double_cat} (H : all_companions_double_cat C) : all_companions (double_cat_to_verity_double_bicat C). Proof. intros x y v. simple refine (_ ,, _). - exact (pr1 (H x y v)). - use double_cat_to_verity_double_bicat_are_companions. exact (pr2 (H x y v)). Defined.
Require Import UniMath.MoreFoundations.All. Require Import UniMath.CategoryTheory.Core.Prelude. Require Import UniMath.CategoryTheory.TwoSidedDisplayedCats.TwoSidedDispCat. Require Import UniMath.Bicategories.Core.Bicat. Import Bicat.Notations. Require Import UniMath.Bicategories.Core.Examples.DiscreteBicat. Require Import UniMath.Bicategories.DoubleCategories.DoubleBicat.Core. Require Import UniMath.Bicategories.DoubleCategories.Basics.DoubleCategoryBasics. Require Import UniMath.Bicategories.DoubleCategories.Core.DoubleCats. Require Import UniMath.Bicategories.DoubleCategories.DerivedLaws.TransportLaws. Require Import UniMath.Bicategories.DoubleCategories.Core.UnivalentDoubleCats. Require Import UniMath.Bicategories.DoubleCategories.Core.CompanionsAndConjoints. Require Import UniMath.Bicategories.DoubleCategories.Underlying.HorizontalBicategory.