∀ {C : Type u} [inst : CategoryTheory.Category.{v, u} C] [inst_1 : CategoryTheory.CartesianMonoidalCategory C]
  {P : CategoryTheory.ObjectProperty C} [inst_2 : P.IsClosedUnderLimitsOfShape (CategoryTheory.Discrete PEmpty.{1})]
  [inst_3 : P.IsClosedUnderLimitsOfShape (CategoryTheory.Discrete CategoryTheory.Limits.WalkingPair)]
  (X Y : P.FullSubcategory),
  (CategoryTheory.MonoidalCategoryStruct.tensorObj X Y).obj =
    CategoryTheory.MonoidalCategoryStruct.tensorObj X.obj Y.obj