> Unfortunately (or suprisingly), even this does not work
> as long as we interpret f = g as  f x = g x  at the top-level:
> 
> f5 (.) g 3 ->* g (g 3)
>            ->  incr (g 3)   (with rule g x = incr x)
>            ->  (g 3) + 1
>            ->  (decr 3) + 1 (with rule g x = decr x)
>            ->* 3
Hmmm, I should have thought of that!
Anyway, here are two more cases. Given the definitions
  coin = 0
  coin = 1
  f6 h g = h g g
  f7 h g = h g0 g0 where g0 = g
what are the solutions of:
  f6 (\x y -> x + y) coin
  f7 (\x y -> x + y) coin
I suppose that 1 is a possible solution in the former case, while it isn't in the latter. (Or will the use of the parameter g for both arguments of h in f6 already introduce sharing?)
Regards
Wolfgang
--
Wolfgang Lux				  Phone: +49-251-83-38263
Institut fuer Wirtschaftinformatik	    FAX: +49-251-83-38259
Universitaet Muenster		Email: lux_at_helios.uni-muenster.de
Received on Mi Dez 02 1998 - 17:49:00 CET