Hint Resolve degree_exp_wrt_exp_close_exp_wrt_exp_rec : lngen.
(* end hide *)

(* Specifications: *)
Lemma degree_exp_wrt_exp_close_exp_wrt_exp :
forall e1 x1,
degree_exp_wrt_exp 0 e1 ->
degree_exp_wrt_exp 1 (close_exp_wrt_exp x1 e1).
Lemma degree_exp_wrt_exp_close_exp_wrt_exp :
forall e1 x1,
degree_exp_wrt_exp 0 e1 ->
degree_exp_wrt_exp 1 (close_exp_wrt_exp x1 e1).