∀ {C : Type u_2} [inst : CategoryTheory.Category.{u_1, u_2} C] [inst_1 : CategoryTheory.CartesianMonoidalCategory C]
  [inst_2 : CategoryTheory.BraidedCategory C] {M : CategoryTheory.Mon C} [inst_3 : CategoryTheory.IsCommMonObj M.X],
  CategoryTheory.CategoryStruct.comp
      (CategoryTheory.MonoidalCategoryStruct.whiskerLeft M { hom := CategoryTheory.MonObj.one, isMonHom_hom := ⋯ })
      { hom := CategoryTheory.MonObj.mul, isMonHom_hom := ⋯ } =
    (CategoryTheory.MonoidalCategoryStruct.rightUnitor M).hom