T2604.hs:7:35:
    Can't make a derived instance of ‛Typeable DList’:
      You need DeriveDataTypeable to derive an instance for this class
    In the data declaration for ‛DList’

T2604.hs:9:38:
    Can't make a derived instance of ‛Typeable NList’:
      You need DeriveDataTypeable to derive an instance for this class
    In the newtype declaration for ‛NList’