Hint Resolve closed_wrt_andp closed_wrtl_andp : closed.

(* Specifications: *)
Lemma closed_wrt_exp: forall {A} S (P: A -> environ->mpred),
(forall a, closed_wrt_vars S (P a)) ->
closed_wrt_vars S (exp P).
Lemma closed_wrtl_exp: forall {A} S (P: A -> environ->mpred),
(forall a, closed_wrt_lvars S (P a)) ->
closed_wrt_lvars S (exp P).