∀ {C : Type u_1} [inst : CategoryTheory.Category.{u_4, u_1} C] {D : Type u_3}
  [inst_1 : CategoryTheory.Category.{u_2, u_3} D] [inst_2 : CategoryTheory.MonoidalCategory D]
  {X Y : CategoryTheory.Functor C (CategoryTheory.Mon D)} (α : X ⟶ Y),
  CategoryTheory.CategoryStruct.comp CategoryTheory.MonObj.one { app := fun X_1 => (α.app X_1).hom, naturality := ⋯ } =
    CategoryTheory.MonObj.one