∀ {C₁ : Type u_8} {C₂ : Type u_4} {C₃ : Type u_6} {C₄ : Type u_2} [inst : CategoryTheory.Category.{u_7, u_8} C₁]
  [inst_1 : CategoryTheory.Category.{u_3, u_4} C₂] [inst_2 : CategoryTheory.Category.{u_5, u_6} C₃]
  [inst_3 : CategoryTheory.Category.{u_1, u_2} C₄] {T : CategoryTheory.Functor C₁ C₂} {L : CategoryTheory.Functor C₁ C₃}
  {R : CategoryTheory.Functor C₂ C₄} {B : CategoryTheory.Functor C₃ C₄} (w : CategoryTheory.TwoSquare T L R B)
  {X₃ : C₃ᵒᵖ} {X₂ : C₂ᵒᵖ} (g : B.op.obj X₃ ⟶ R.op.obj X₂) (f : (w.op.StructuredArrowRightwards g)ᵒᵖ),
  CategoryTheory.CategoryStruct.comp (R.map (Opposite.unop f).right.hom.unop)
      (CategoryTheory.CategoryStruct.comp (w.app (Opposite.unop (Opposite.unop f).right.left))
        (B.map (Opposite.unop f).hom.left.unop)) =
    g.unop