help wanted with type error message

[Simon Peyton-Jones]

| A third extension which is ocasionally useful is not present=20
| in any Haskell implementation. I would like to say
|     instance (forall a. Seq (s a) a) =3D> Foo (Bar s)
| It would allow to e.g. wrap my collections in Edison's=20
| interfaces, not only vice versa.

Yes, indeed.  See Section 7 of
	http://research.microsoft.com/~simonpj/Papers/derive.htm

We havn't implemented it yet, I fear.

Simon