∀ {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)
  (f : M ⟶ CategoryTheory.MonoidalCategoryStruct.tensorUnit (CategoryTheory.Mon C)),
  f = (fun M => { hom := CategoryTheory.SemiCartesianMonoidalCategory.toUnit M.X, isMonHom_hom := ⋯ }) M