(** Inclusion *)

Definition vpincl (v: aval) (p: aptr) : bool :=
  match v with
  | Ptr q | Ifptr q | Uns q _ | Sgn q _ => pincl q p
  | _ => true
  end.

Lemma vpincl_sound: forall v x p, vpincl x p = true -> vmatch v x -> vmatch v (Ifptr p).