proposition: Lemma assoc_step_4 : linvunitor_h _ ⋆h id_v_square _ ⋆v ((s₁ ⋆h s₂) ⋆h s₃ ⋆v lunitor_h _ ⋆h id_v_square _) = (linvunitor_h (identity_h x) ⋆v ((s₁ ⋆h s₂) ⋆v lunitor_h (identity_h y))) ⋆h (id_v_square _ ⋆v (s₃ ⋆v id_v_square _)).
proof: Proof. rewrite <- !comp_h_square_comp. apply idpath. Qed.
imports: UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Prelude UniMath.CategoryTheory.Core.Setcategories UniMath.CategoryTheory.Core.TwoCategories UniMath.CategoryTheory.Monads.Monads UniMath.CategoryTheory.TwoSidedDisplayedCats.TwoSidedDispCat UniMath.CategoryTheory.TwoSidedDisplayedCats.Isos UniMath.CategoryTheory.TwoSidedDisplayedCats.Univalence UniMath.CategoryTheory.TwoSidedDisplayedCats.Strictness UniMath.CategoryTheory.TwoSidedDisplayedCats.Examples.Comma UniMath.Bicategories.Core.Bicat UniMath.Bicategories.Core.Examples.BicatOfUnivCats UniMath.Bicategories.DoubleCategories.Basics.DoubleCategoryBasics UniMath.Bicategories.DoubleCategories.Core.DoubleCats UniMath.Bicategories.DoubleCategories.Core.UnivalentDoubleCats UniMath.Bicategories.DoubleCategories.Core.PseudoDoubleSetCats UniMath.Bicategories.DoubleCategories.DerivedLaws