proposition: Fact mb_equiv_mem x y : x ≈ y -> forall z, x ∈ z <-> y ∈ z.
proof: Proof. Proof using mb_axiom_ext. split; apply mb_axiom_ext; auto. Qed.
imports: List Arith Nat Lia Max Wellfounded Coq.Setoids.Setoid Undecidability.Shared.Libs.DLW.Utils(utils_tac utils_list finite) Undecidability.Shared.Libs.DLW.Vec(pos vec) Undecidability.FOL.TRAKHTENBROT(notations fol_ops fo_sig fo_terms fo_logic)