proposition: Fact bti_inv_0 x : x ⊆ ∅ <-> x = ∅.
proof: Proof. split; intros H; subst; auto. destruct x as [ | s t ]; auto. specialize (H s); revert H; btm simpl. intros []; auto. Qed.
imports: List Arith Lia Max Wellfounded Setoid Eqdep_dec Undecidability.Shared.Libs.DLW.Utils(utils_tac utils_list utils_decidable finite seteq) Undecidability.Shared.Libs.DLW.Vec(pos) Undecidability.Shared.Libs.DLW.Wf(wf_finite wf_chains) Undecidability.FOL.TRAKHTENBROT(notations fol_ops)