Section dfunctor_def.
Variables (A B : Category) (F : Functor A B).
Definition DFunctor_ob : Dual A -> Dual B := fun a : A => F a.
Definition DFunctor_map (b a : A) := FMap F a b.

Lemma DFunctor_comp_law : Fcomp_law (FOb:=DFunctor_ob) DFunctor_map.