proposition: Fact hfs_card_pos_spec n x Hx : x = hfs_pos (@hfs_card_pos n x Hx).
proof: Proof. unfold hfs_card_pos, hfs_pos. symmetry; apply bt_cls_hfs_repr_iff. rewrite bt2pos_fix; 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)