∀ {C : Type u_1} [inst : CategoryTheory.Category.{u_3, u_1} C] [inst_1 : CategoryTheory.MonoidalCategory C]
  {D : Type u_8} [inst_2 : CategoryTheory.Category.{u_6, u_8} D] [inst_3 : CategoryTheory.MonoidalCategory D]
  {E : Type u_2} [inst_4 : CategoryTheory.Category.{u_4, u_2} E] [inst_5 : CategoryTheory.MonoidalCategory E]
  {C' : Type u_7} [inst_6 : CategoryTheory.Category.{u_5, u_7} C'] (F : CategoryTheory.Functor C D)
  (G : CategoryTheory.Functor E C') [inst_7 : CategoryTheory.MonoidalCategory C'] [inst_8 : F.LaxMonoidal]
  [inst_9 : G.LaxMonoidal] {X Y : C × E} (X' : C × E) (f : X ⟶ Y),
  CategoryTheory.CategoryStruct.comp
      (CategoryTheory.MonoidalCategoryStruct.whiskerLeft ((F.prod G).obj X') ((F.prod G).map f))
      (CategoryTheory.Prod.mkHom (CategoryTheory.Functor.LaxMonoidal.μ F X'.1 Y.1)
        (CategoryTheory.Functor.LaxMonoidal.μ G X'.2 Y.2)) =
    CategoryTheory.CategoryStruct.comp
      (CategoryTheory.Prod.mkHom (CategoryTheory.Functor.LaxMonoidal.μ F X'.1 X.1)
        (CategoryTheory.Functor.LaxMonoidal.μ G X'.2 X.2))
      ((F.prod G).map (CategoryTheory.MonoidalCategoryStruct.whiskerLeft X' f))