proposition: Proposition comp_h_square_id {C : double_cat} {x y z : C} (h₁ : x -->h y) (h₂ : y -->h z) : id_v_square h₁ ⋆h id_v_square h₂ = id_v_square (h₁ ·h h₂).
proof: Proof. apply double_hor_comp_mor_id. Defined.
imports: UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Categories UniMath.CategoryTheory.Core.Functors UniMath.CategoryTheory.Core.NaturalTransformations UniMath.CategoryTheory.Core.Isos UniMath.CategoryTheory.TwoSidedDisplayedCats.TwoSidedDispCat UniMath.CategoryTheory.TwoSidedDisplayedCats.Isos UniMath.CategoryTheory.TwoSidedDisplayedCats.Univalence UniMath.Bicategories.Core.Examples.BicatOfUnivCats UniMath.Bicategories.DoubleCategories.Basics.DoubleCategoryBasics