fact: Definition square_between_companions {B : verity_double_bicat} {x y : B} {h : x --> y} {v₁ v₂ : x -|-> y} (c₁ : are_companions h v₁) (c₂ : are_companions h v₂) : square_double_bicat (id_h x) (id_h y) v₁ v₂ := linvunitor _ ◃s (runitor _ ▹s counit_are_companions c₂ ⋆v unit_are_companions c₁).
imports: UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Prelude UniMath.Bicategories.Core.Bicat UniMath.Bicategories.Core.Unitors UniMath.Bicategories.Core.Invertible_2cells UniMath.Bicategories.Core.Univalence UniMath.Bicategories.Core.BicategoryLaws UniMath.Bicategories.Morphisms.Adjunctions UniMath.Bicategories.DoubleCategories.DoubleBicat.VerityDoubleBicat UniMath.Bicategories.DoubleCategories.DoubleBicat.DerivedLaws UniMath.Bicategories.DoubleCategories.DoubleBicat.CellsAndSquares UniMath.Bicategories.DoubleCategories.DoubleBicat.UnderlyingCats UniMath.Bicategories.DoubleCategories.DoubleBicat.LocalUnivalence UniMath.Bicategories.DoubleCategories.DoubleBicat.CompanionPairs