proposition: Fact Σ_fin_syms : forall s : syms Σ', In (proj1_sig s) ls.
proof: Proof. intros (s & Hs); apply HFn, Hs. Qed.
imports: List Arith Bool Lia Eqdep_dec Max Undecidability.Shared.Libs.DLW.Utils(utils_tac utils_list utils_nat finite) Undecidability.Shared.Libs.DLW.Vec(pos vec) Undecidability.FOL.TRAKHTENBROT(notations utils decidable fol_ops fo_sig fo_terms fo_logic fo_sat)