English
The divided faithful functor is faithful if F is faithful and G is faithful with appropriate data.
Русский
Разделённый верный функтор верен, если F и G верны и данные соответствуют условиям.
LaTeX
$$$\text{Faithful.div } F G obj h_obj map h_map\text{ is faithful}$$$
Lean4
theorem div_faithful (F : C ⥤ E) [F.Faithful] (G : D ⥤ E) [G.Faithful] (obj : C → D)
(h_obj : ∀ X, G.obj (obj X) = F.obj X) (map : ∀ {X Y}, (X ⟶ Y) → (obj X ⟶ obj Y))
(h_map : ∀ {X Y} {f : X ⟶ Y}, G.map (map f) ≍ F.map f) :
Functor.Faithful (Faithful.div F G obj @h_obj @map @h_map) :=
(Faithful.div_comp F G _ h_obj _ @h_map).faithful_of_comp