proposition: Lemma close_exp_wrt_exp_rec_degree_exp_wrt_exp : forall e1 x1 n1, degree_exp_wrt_exp n1 e1 -> x1 `notin` fv_exp e1 -> close_exp_wrt_exp_rec n1 x1 e1 = e1.
proof: Proof. pose proof close_exp_wrt_exp_rec_degree_exp_wrt_exp_mutual as H; intuition eauto. Qed.
imports: Coq.Logic.FunctionalExtensionality Coq.Program.Equality Metalib.Metatheory Metalib.LibLNgen Stlc