proposition: Lemma close_exp_wrt_exp_rec_open_exp_wrt_exp_rec : forall e1 x1 n1, x1 `notin` fv_exp e1 -> close_exp_wrt_exp_rec n1 x1 (open_exp_wrt_exp_rec n1 (var_f x1) e1) = e1.
proof: Proof. pose proof close_exp_wrt_exp_rec_open_exp_wrt_exp_rec_mutual as H; intuition eauto. Qed.
imports: Coq.Logic.FunctionalExtensionality Coq.Program.Equality Metalib.Metatheory Metalib.LibLNgen Stlc