Haskell' - class aliases

[Jacques Carette]

I tried to see the discussion that led to class aliases being rejected 
as a proposal, but could not find links on the Wiki.  In fact, in Trac 
(#101) that proposal is still a 'maybe', but with no updates.  Is there 
a competing proposal that got accepted?

[Without a mechanism like class aliases, breaking up Num into a 
hierarchy of proper mathematical concepts becomes too unwieldly to be 
realistic.  This is a real stumbling block for anyone trying to use the 
class system to encode fine-grained mathematical concepts.]

Jacques