G'day all.

Quoting Simon Peyton-Jones <[EMAIL PROTECTED]>:

> I've considered this before, but never done anything about it because
> superclasses are so close.  Specifically, what is the difference between
>
> (i)   class (C a, D a) => CD a
> and
> (ii)  class alias CD a = (C a, D a)
>
> Note that (i) is Haskell 98.

To be a true typeclass synonym, there would also be an implied default
instance:

    class (C a, D a) => CD a
    instance (C a, D a) => CD a

...and this is not Haskell 98.

Cheers,
Andrew Bromage
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