∀ {C : Type u_2} [inst : CategoryTheory.Category.{u_1, u_2} C] {W Y S T : C} (f₁ : W ⟶ S) (g₁ : Y ⟶ T) (i₁ : W ⟶ Y)
  (i₃ : S ⟶ T),
  CategoryTheory.CategoryStruct.comp f₁ i₃ = CategoryTheory.CategoryStruct.comp i₁ g₁ →
    CategoryTheory.CategoryStruct.comp g₁.op i₁.op = CategoryTheory.CategoryStruct.comp i₃.op f₁.op