proposition: Proposition square_id_left_v {C : double_cat} {x₁ x₂ y₁ y₂ : C} {v₁ : x₁ -->v y₁} {v₂ : x₂ -->v y₂} {h₁ : x₁ -->h x₂} {h₂ : y₁ -->h y₂} (s : square v₁ v₂ h₁ h₂) : id_v_square h₁ ⋆v s = transportb_square (id_left _) (id_left _) s.
proof: Proof. apply id_two_disp_left. 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