
tcfail117.hs:5:32:
    Can't make a derived instance of `Enum N1':
      `N1' must be an enumeration type
      (an enumeration consists of one or more nullary, non-GADT constructors)
      Try -XGeneralizedNewtypeDeriving for GHC's newtype-deriving extension
    In the newtype declaration for `N1'

tcfail117.hs:6:32:
    Can't make a derived instance of `Enum N2':
      `N2' must be an enumeration type
      (an enumeration consists of one or more nullary, non-GADT constructors)
    In the data type declaration for `N2'
