∀ {C : Type u} [inst : CategoryTheory.Category.{v, u} C] [inst_1 : CategoryTheory.MonoidalCategory C] (X Y : C) {Z : C}
  (h : CategoryTheory.MonoidalCategoryStruct.tensorObj X Y ⟶ Z),
  CategoryTheory.CategoryStruct.comp
      (CategoryTheory.MonoidalCategoryStruct.rightUnitor (CategoryTheory.MonoidalCategoryStruct.tensorObj X Y)).hom h =
    CategoryTheory.CategoryStruct.comp
      (CategoryTheory.MonoidalCategoryStruct.associator X Y (CategoryTheory.MonoidalCategoryStruct.tensorUnit C)).hom
      (CategoryTheory.CategoryStruct.comp
        (CategoryTheory.MonoidalCategoryStruct.whiskerLeft X (CategoryTheory.MonoidalCategoryStruct.rightUnitor Y).hom)
        h)