(** Matching and [let]-bound variables. *)

(* Specifications: *)
Lemma match_env_bind_letvar:
forall map e le rs r v,
match_env map e le rs ->
Val.lessdef v rs#r ->
match_env (add_letvar map r) e (v :: le) rs.
Lemma match_env_unbind_letvar:
forall map e le rs r v,
match_env (add_letvar map r) e (v :: le) rs ->
match_env map e le rs.