Hi Very very helpful, thanks. I wasnt sure about the "From" on the end, but I get the subtle change in way you see it. Much better than mine. Using you other advice I got: gaSolutionSpaceFrom :: a -> [a] gaSolutionSpaceFrom p = iterate evolvePopulation p and even managed to curry it :-) : gaSolutionSpaceFrom :: a -> [a] gaSolutionSpaceFrom = iterate evolvePopulation Thanks again. -------------- Kieth: [Snip] I think you mean: gaSolutionSpaceFrom :: a -> [a] gaSolutionSpaceFrom x = x : gaSolutionSpaceFrom (evolvepopulation x) gaSolutionSpace = gaSolutionSpaceFrom createRandomPopulation Note that "a" above should be replaced with your population type. Also note the "iterate" function in the standard library does just this. _________________________________________________________________ Tired of spam? Get advanced junk mail protection with MSN 8. http://join.msn.com/?page=features/junkmail