Overlapping instances

[Simon Peyton-Jones]

There has been a great deal of mail about overlapping 
instances.  I confess that I have read little of it.
But I am interested in it.  

        Would someone like to write a summary of
                what the issues are
                what people agree about
                what they disagree about
        (as briefly as poss)?

I think that such a summary would be helpful for those
Haskell mailing list readers who have not been following the
detail.  I don't want to start a new debate, just to find
out what happened in the existing discussion.

Simon