∀ {C : Type u_4} [inst : CategoryTheory.Category.{u_3, u_4} C] {T : CategoryTheory.Monad C} {J : Type u_2}
  [inst_1 : CategoryTheory.Category.{u_1, u_2} J] (D : CategoryTheory.Functor J T.Algebra) ⦃X Y : J⦄ (f : X ⟶ Y),
  CategoryTheory.CategoryStruct.comp ((D.comp (T.forget.comp T.toFunctor)).map f) (D.obj Y).a =
    CategoryTheory.CategoryStruct.comp (D.obj X).a ((D.comp T.forget).map f)