Program Definition Twist_Func (C C' : Category) : (C × C') –≻ (C' × C) :=
{|
FO := fun a => (snd a, fst a);
FA := fun _ _ f => (snd f, fst f);
F_id := fun _ => eq_refl;
F_compose := fun _ _ _ _ _ => eq_refl
|}.
Section Twist_Prod_Func_Twist.
Context {C C' : Category} (F : C –≻ C') {D D' : Category} (G : D –≻ D').

(* Specifications: *)
Theorem Twist_Prod_Func_Twist :
(((Twist_Func _ _) ∘ (Prod_Functor F G)) ∘ (Twist_Func _ _))%functor =
Prod_Functor G F.