(*  The powerset and its axioms   *)

Definition Power (E : Ens) : Ens :=
  match E with
  | sup A f =>
      sup _
        (fun P : A -> Prop =>
         sup _
           (fun c : depprod A (fun a : A => P a) =>
            match c with
            | dep_i a p => f a
            end))
  end.

Theorem Power_mon : forall E E' : Ens, INC E E' -> INC (Power E) (Power E').