proposition: Theorem FSAT_REL_2ton n : 2 <= n -> FSAT (Σrel 2) ⪯ᵢ FSAT (Σrel n).
proof: Proof. revert n; intros [ | [ | n ] ] H; try (exfalso; lia). exists (Σ2_Σn n); intros A; split. + apply Σ2_Σn_soundness. + apply Σ2_Σn_completeness. Qed.
imports: List Arith Bool Lia Eqdep_dec Undecidability.Synthetic.Definitions Undecidability.Synthetic.ReducibilityFacts Undecidability.Synthetic.InformativeDefinitions Undecidability.Synthetic.InformativeReducibilityFacts Undecidability.Shared.Libs.DLW.Utils(utils_tac utils_list utils_nat finite) Undecidability.Shared.Libs.DLW.Vec(pos vec) Undecidability.Shared.Libs.DLW.Wf(wf_finite) Undecidability.FOL.TRAKHTENBROT(notations utils decidable bpcp fo_sig fo_terms fo_logic fo_sat red_utils Sig_discrete BPCP_SigBPCP Sig_rem_syms Sig_uniform Sig_one_rel Sig_rem_cst Sign_Sig2 Sig2_Sign Sign_Sig Sig_Sig_fin Sig2_SigSSn1 Sign1_Sig )