∀ {C : Type u} [inst : CategoryTheory.Category.{v, u} C] [inst_1 : CategoryTheory.Limits.HasFiniteProducts C]
  [inst_2 : CategoryTheory.Limits.HasPullbacks C] (X Y : CategoryTheory.Dial C),
  (CategoryTheory.MonoidalCategoryStruct.tensorObj X Y).src = (X.src ⨯ Y.src)