∀ {C : Type u₁} [inst : CategoryTheory.Category.{v₁, u₁} C] [inst_1 : CategoryTheory.MonoidalCategory C]
  (X : CategoryTheory.Center C),
  (CategoryTheory.MonoidalCategoryStruct.rightUnitor X).hom.f =
    (CategoryTheory.MonoidalCategoryStruct.rightUnitor X.fst).hom