Hint Resolve closed_wrt_TT closed_wrtl_TT : closed.

(* Specifications: *)
Lemma closed_wrt_subset:
forall (S S': ident -> Prop) (H: included S' S) B (f: environ -> B),
closed_wrt_vars S f -> closed_wrt_vars S' f.
Lemma closed_wrtl_subset:
forall (S S': ident -> Prop) (H: included S' S) B (f: environ -> B),
closed_wrt_lvars S f -> closed_wrt_lvars S' f.