proposition: Lemma open_exp_wrt_exp_rec_inj : forall e2 e1 x1 n1, x1 `notin` fv_exp e2 -> x1 `notin` fv_exp e1 -> open_exp_wrt_exp_rec n1 (var_f x1) e2 = open_exp_wrt_exp_rec n1 (var_f x1) e1 -> e2 = e1.
proof: Proof. pose proof open_exp_wrt_exp_rec_inj_mutual as H; intuition eauto. Qed.
imports: Coq.Logic.FunctionalExtensionality Coq.Program.Equality Metalib.Metatheory Metalib.LibLNgen Stlc