Bits Problem

[Dominic Steinitz]

Can anyone explain this? Hugs doesn't complain.

Prelude> :set --version
The Glorious Glasgow Haskell Compilation System, version 5.04.1

test.hs:5:
    No instance for (Num Bool)
    arising from the instance declaration at test.hs:5
    In the instance declaration for `Bits Bool'

module Main(main) where

import Bits

instance Bits Bool where
   complement False = True
   complement True  = False

Dominic Steinitz