proposition: Lemma enc_derivations_base R n : HFeq ⊢ {{∅; ∅}; {∅; enc_stack R}} ∈ enc_derivations R n.
proof: Proof. induction n; cbn. - apply HF_sing_el. - apply HF_bunion_el. now apply DI1. Qed.
imports: Undecidability.FOL.ZF Undecidability.FOL.Syntax.Facts Undecidability.FOL.Semantics.Tarski.FullFacts Undecidability.FOL.Sets.ZF Undecidability.FOL.Reductions.PCPb_to_HF Undecidability.PCP(PCP Util.PCP_facts Reductions.PCPb_iff_dPCPb) Undecidability(Shared.ListAutomation)