∀ {C : Type u_1} {D : Type u_2} {E : Type u_3} [inst : CategoryTheory.Category.{v_1, u_1} C]
  [inst_1 : CategoryTheory.Category.{v_2, u_2} D] [inst_2 : CategoryTheory.Category.{v_3, u_3} E]
  [inst_3 : CategoryTheory.Preadditive C] [inst_4 : CategoryTheory.Preadditive D]
  [inst_5 : CategoryTheory.Preadditive E] (F : CategoryTheory.Functor C D) (G : CategoryTheory.Functor D E) [G.Additive]
  [(F.comp G).Additive] [G.Faithful], F.Additive