Anton Moscal writes:
> Hello!
>
> This is well-known definition of the existential quantification
> through universal:
>
> (E x.P(x)) <=> A y.(A x.P (x) => y) => y
>
> I try to translate in to Haskell. The following program can be
> compiled by "ghc -fglasgow-exts ..." and works correctly:
>
[...]
> main = print (map eval [mk_app (\x->x) 239, mk_app Char.ord '1'])
import Char(ord)
main = print (tail [error "I'm too lazy to be explicitly existential.",
(\x->x) 239,
ord '1'])
{- Regards, Tom :-}
_______________________________________________
Haskell mailing list
[EMAIL PROTECTED]
http://www.haskell.org/mailman/listinfo/haskell
