[TYPES] union types and overloading

[Kwangkeun Yi]

Hi Johan,

Thanks for your reply. 

> Note that the declaration of type Both is necessary in this system.  
> Note also that the argument to constructor B is still of type T1, even 
> when B is considered a constructor of type Both.

My plan roughly agrees with O'Haskell's design decision, except for one thing:
the Both declartion from the programmer. Quick question: for what did
you trade the no-extra-annotation? (Maybe I have to study your papers, but for
quick answers...)

All the best,

-Kwang

-- 
Kwangkeun Yi		http://ropas.snu.ac.kr/~kwang