Type classes in GADTs

[Thomas Schilling]

2008/10/30 C Rodrigues <red5_2 at hotmail.com>:
> evidenceOfEq :: CAOp a -> (Eq a => b) -> b

isn't that the same as:

  evidenceOfEq :: Eq a => CAOp a -> b -> b


> Neither does it accept data EqConstraint a b = EqConstraint (Eq a => b).  Foiled again.

same here:

  data Eq a => EqConstraint a b = EqConstraint b.

although this must be a typo, since it doesn't make any sense to me.