> GHC (5.03.20020410) wrongly accepts the following:
>
> ::
> C.lhs
> ::
> > module C
> > where
>
> > class A a where
> > a :: a -> Int
> ::
> X.lhs
> ::
> > module X
> > where
> > import qualified C
>
> > instance C.A Int where
> > C.a = id
For those puzzled by the number of things called 'a' in Ralf's
program, I'm attaching an alpha-renamed version. Removing the type
signature (or changing the type signature to Integer) for a results in
Ralf's type error in Hugs.
It does indeed look as though Hugs applies defaulting to 'a' and
