proposition: Proposition strict_square_assoc {C : strict_double_cat} {w₁ w₂ x₁ x₂ y₁ y₂ z₁ z₂ : C} {vw : w₁ -->v w₂} {vx : x₁ -->v x₂} {vy : y₁ -->v y₂} {vz : z₁ -->v z₂} {h₁ : w₁ -->h x₁} {h₂ : x₁ -->h y₁} {h₃ : y₁ -->h z₁} {k₁ : w₂ -->h x₂} {k₂ : x₂ -->h y₂} {k₃ : y₂ -->h z₂} (s₁ : s_square vw vx h₁ k₁) (s₂ : s_square vx vy h₂ k₂) (s₃ : s_square vy vz h₃ k₃) : s₁ ⋆h (s₂ ⋆h s₃) = transportb_s_square (idpath _) (idpath _) (s_assocl_h _ _ _) (s_assocl_h _ _ _) ((s₁ ⋆h s₂) ⋆h s₃).
proof: Proof. apply (pr222 (pr222 C) w₁ w₂ x₁ x₂ y₁ y₂ z₁ z₂ vw vx vy vz h₁ h₂ h₃ k₁ k₂ k₃ s₁ s₂ s₃). Defined.
imports: UniMath.MoreFoundations.All UniMath.CategoryTheory.Core.Prelude UniMath.CategoryTheory.Core.Setcategories UniMath.CategoryTheory.Categories.CategoryOfSetCategories UniMath.CategoryTheory.whiskering UniMath.CategoryTheory.DisplayedCats.Core UniMath.CategoryTheory.DisplayedCats.Functors UniMath.CategoryTheory.DisplayedCats.NaturalTransformations UniMath.CategoryTheory.DisplayedCats.Isos UniMath.CategoryTheory.DisplayedCats.Total UniMath.CategoryTheory.DisplayedCats.Univalence UniMath.CategoryTheory.DisplayedCats.Constructions UniMath.CategoryTheory.DisplayedCats.Examples.StrictTwoSidedDispCat UniMath.CategoryTheory.TwoSidedDisplayedCats.TwoSidedDispCat UniMath.CategoryTheory.TwoSidedDisplayedCats.DisplayedFunctor UniMath.CategoryTheory.TwoSidedDisplayedCats.DisplayedNatTrans UniMath.CategoryTheory.TwoSidedDisplayedCats.Isos UniMath.CategoryTheory.TwoSidedDisplayedCats.Univalence UniMath.CategoryTheory.TwoSidedDisplayedCats.Strictness UniMath.CategoryTheory.TwoSidedDisplayedCats.TransportLaws UniMath.Bicategories.DoubleCategories.Basics.DoubleCategoryBasics UniMath.Bicategories.DoubleCategories.Basics.StrictDoubleCatBasics UniMath.Bicategories.DoubleCategories.Core.CatOfStrictDoubleCats