proposition: Fact btm_repr_cls t s : t ∈ cls s <-> bt_mem (repr t) s.
proof: Proof. generalize (bt_norm_eq s). simpl; split; apply btm_congr_r; 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)