fact: Fixpoint enc_derivations B n := match n with | O => sing (opair ∅ (enc_stack B)) | S n => opair (tnumeral (S n)) (enc_stack (derivations B (S n))) ::: enc_derivations B n end.
imports: Undecidability.FOL.Syntax.Facts Undecidability.FOL.Semantics.Tarski.FullFacts Undecidability.FOL.Deduction.FullNDFacts Undecidability.FOL.Sets.FST Undecidability.FOL.FST Undecidability.FOL.Reductions.PCPb_to_FST Undecidability.PCP(PCP Util.PCP_facts Reductions.PCPb_iff_dPCPb) Undecidability(Shared.ListAutomation)