proposition: Lemma subsetb_spec A P : subsetb A P = forallb (my_inb P) A.
proof: Proof. induction A; cbn; congruence. Qed.
imports: Undecidability.Synthetic(Definitions EnumerabilityFacts ListEnumerabilityFacts) Lia Undecidability.L(LProd LBool LNat LOptions) Undecidability.L.Datatypes.List(List_basics List_eqb List_extra List_nat) Undecidability(PCP)