proposition: Fact bt_cls_hfs_repr_iff t s : cls t = s <-> t ≈ repr s.
proof: Proof. rewrite <- (bt_cls_hfs_repr s) at 1. apply bt_cls_equiv. 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)