fact: Definition cons' {X} : X * list X -> list X := fun '(pair x L0) => cons x L0.
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)