∀ {V : Type u_1} [inst : CategoryTheory.Category.{v_1, u_1} V] {W : Type u_2}
  [inst_1 : CategoryTheory.Category.{v_2, u_2} W] (G : Type u_3) [inst_2 : Monoid G] {T : Type u_4}
  [inst_3 : CategoryTheory.Category.{v_3, u_4} T] (F : CategoryTheory.Functor V W) (F' : CategoryTheory.Functor W T),
  (CategoryTheory.Functor.mapActionComp G F F').hom =
    { app := fun X => CategoryTheory.CategoryStruct.id (((F.comp F').mapAction G).obj X), naturality := ⋯ }