fact: Definition sum_enum {X Y} (f1 : nat -> option X) (f2 : nat -> option Y) n : option (X + Y) := match Cantor.of_nat n with | (0, m) => option_map inl (f1 m) | (1, m) => option_map inr (f2 m) | _ => None end.
imports: Undecidability.Synthetic(DecidabilityFacts SemiDecidabilityFacts) Undecidability.Shared.Libs.PSL.FiniteTypes.FinTypesDef Vector List Lia