[Haskell-cafe] Overlapping/Incoherent instances

[J. Garrett Morris]

Hello everyone,

As part of a project to formalize the theory of overlapping instances,
I'm looking for examples of overlapping and incoherent instances and
their usage.  One such example would be the old version of the Monad
Transformer Library, which used overlapping instances together with
MonadTrans.  Any other examples or suggestions would be greatly
appreciated!

Thanks,

 /g