Mismatched contexts

Armin Größlinger writes:
 :
 | GHC says
 | 
 |     Mismatched contexts
 |     When matching the contexts of the signatures for
 |       functions :: Functions
 |       f2a :: forall a. (Integral a) => a -> a
 |     The signature contexts in a mutually recursive group
 |       should all be identical
 |     When generalising the type(s) for functions, f2a
 :
 | I don't understand why the contexts must be identical in mutually
 | recursive definitions.
 :

Hi.

I don't know why that particular example was rejected, but if you're
after some general discussion of contexts in mutually recursive
groups, see section 11.6.3 of Typing Haskell in Haskell
(http://www.cse.ogi.edu/~mpj/thih/).

Regards,
Tom