fact: Variable (ν : nat -> nat).
imports: List Arith Lia Max Undecidability.Synthetic.Definitions Undecidability(Shared.Libs.DLW.Utils.utils H10.Dio.dio_logic H10.Dio.dio_elem) Undecidability(H10.FRACTRAN_DIO FRACTRAN.FRACTRAN) Undecidability.DiophantineConstraints.H10C