proposition: Theorem PCPb_deduction_ZF' : PCPb ⪯ deduction_ZF'.
proof: Proof. exists solvable. intros B. split; try apply PCP_ZFD. intros H' % soundness. apply PCP_ZFeq'; try apply intensional_model. intros D M rho H. apply H', H. Qed.
imports: Undecidability.Synthetic.Definitions Undecidability.Synthetic.Undecidability Undecidability.FOL(Semantics.Tarski.FullFacts Semantics.Tarski.FullSoundness) Undecidability.FOL.Sets.Models(Aczel_CE Aczel_TD ZF_model HF_model) Undecidability.FOL.Reductions(ZF_to_HF PCPb_to_HF PCPb_to_HFD PCPb_to_ZFeq PCPb_to_ZF PCPb_to_ZFD) Undecidability.FOL.Sets.ZF Undecidability.FOL.ZF Undecidability.PCP(PCP PCP_undec Util.PCP_facts Reductions.PCPb_iff_dPCPb)