proposition: Fact bt_cls_eq_norm s t : bt_cls s = bt_cls t <-> bt_norm s = bt_norm t.
proof: Proof. simpl; split. + inversion 1; auto. + intro; apply bt_norm_exist; auto. Qed.
imports: List Arith Lia Max Wellfounded Setoid Eqdep_dec Bool Undecidability.Shared.Libs.DLW.Utils(utils_tac utils_list finite) Undecidability.Shared.Libs.DLW.Vec(pos vec) Undecidability.Shared.Libs.DLW.Wf(wf_finite wf_chains) Undecidability.FOL.TRAKHTENBROT(notations fol_ops membership btree)