proposition: Fact bt_lt_eq_lt_dec s t : { s ≺ t } + { s = t } + { t ≺ s }.
proof: Proof. revert t; induction s as [ | s1 H1 s2 H2 ]; intros [ | t1 t2 ]; auto. destruct (H1 t1) as [ [] | ]; auto; destruct (H2 t2) as [ [] | ]; subst; 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)