∀ {C : Type u₁} [inst : CategoryTheory.Category.{v₁, u₁} C] {D : Type u₂} [inst_1 : CategoryTheory.Category.{v₂, u₂} D]
  {F G : CategoryTheory.Functor C D} (h : F = G) {X Y : C} (f : X ⟶ Y),
  F.map f =
    CategoryTheory.CategoryStruct.comp (CategoryTheory.eqToHom ⋯)
      (CategoryTheory.CategoryStruct.comp (G.map f) (CategoryTheory.eqToHom ⋯))