(Re-sending. Does this list drop mail from non-subscribers?)

I've seen the hugs distribution that is hosted as

http://ndmitchell.googlecode.com/files/MinHugs-Sep2006.exeand has the SHA1 checksum 02f62efe00334007eb7083d09bae6e692a48c7c2

evaluate the script below incorrectly on two different Windows XP

computers.

The correct output is [], but I get a non-empty list. On one

computer

I get different output for successive runs of the same script

(restarting hugs) by saying "main". On the other one I get

different

output by saying "main" versus "ls".

I can't reproduce the problem on two different UNIX-like systems

with

the September 2006 version of hugs. The problem goes away by

replacing

"Integer" with "Int".

type Z = Integer

qs :: Z -> Z

qs 0 = 0

qs x = let (q,r) = divMod x 10 in r + qs q

iqs :: Z -> Z

iqs x = if x < 10 then x else iqs (qs x)

ok :: Z -> Z -> Bool

ok x y = iqs (iqs x * iqs y) == iqs (x*y)

n :: Z

n = 1000

ls :: [(Z,Z)]

ls = [(x,y) | x<-[1..n], y<-[x..n], not (ok x y)]

main = print ls

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