I've just tried writing a small code uses a function (/). When hugs compiled it, it turned out that the type declaration is the error. For function every function (/) you had to use type class Fractional it says. But do we have to use Fractional every time we include (/)? the code is as follows: more_less :: [(Int,Int)] -> ([(Int,Int)],[(Int,Int)]) more_less x = ([ m | m <- x, map (snd x) >= mean x], [ l | l <- x, map (snd x) < mean x] where mean x = (sum (map snd x))/(length x) What the code is intended to do is take a list of [(Int,Int)] and sort out the list in terms of their second value compared to the mean of the mean of the second values. I look forward to hearing from everyone. Thanks Cheers, Anthony Sign up for your FREE E-MAIL @ COMETMAIL: http://www.cometmail.com