proposition: Fact fol_def_True : fol_definable (fun _ => True).
proof: Proof. exists (⊥⤑⊥); intros; simpl; msplit 2; try red; simpl; tauto. Qed.
imports: List Arith Lia Undecidability.Shared.Libs.DLW.Utils(utils_tac utils_list finite) Undecidability.Shared.Libs.DLW.Vec(pos vec) Undecidability.FOL.TRAKHTENBROT(notations utils fol_ops fo_sig fo_terms fo_logic)