Anomalous Class Fundep Inference

[Ashley Yakeley]

At 2001-05-03 01:42, Simon Peyton-Jones wrote:

>Quite right too!

OK, I understand it a bit better now. This code does not compile:
--
class X a
instance X Bool
instance (Num a) => X a
--
Can someone explain why the two instances overlap, given that Bool is not 
an instance of Num?

Would it be possible for Haskell to figure out this sort of thing and not 
complain about it, or would that lead to nasty problems?

-- 
Ashley Yakeley, Seattle WA