Hint Resolve degree_exp_wrt_exp_S : lngen.

(* Specifications: *)
Lemma degree_exp_wrt_exp_O :
forall n1 e1,
degree_exp_wrt_exp O e1 ->
degree_exp_wrt_exp n1 e1.
Lemma degree_exp_wrt_exp_O :
forall n1 e1,
degree_exp_wrt_exp O e1 ->
degree_exp_wrt_exp n1 e1.