proposition: Fact btm_opair_pow x y t : x ∈ t -> y ∈ t -> ⟬x,y⟭ ∈ bt_pow (bt_pow t).
proof: Proof. rewrite bt_pow_spec. intros ? ? ?. rewrite bt_opair_spec; intros [-> | ->]; apply bt_pow_spec. + intro; btm simpl; intros [ -> | [] ]; auto. + intro; 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)