Disjunctive tuples

[Yitzchak Gale]

Thomas Davie wrote:
> To appease those who I know think that Haskell
> is over-complicated already and should be
> having things removed

I am one of those. But it is interesting that '|'
means the same thing here as it does in ADTs.
So it does add consistency.

On the other hand, if we envision GADTs supplanting
ADTs entirely someday, then this will become an
anomaly.

The disjunctive 2-tuple has a natural monad instance
as an exit monad.

-Yitz