main :: [sys_message]
main = [Stdout (lay (map show (comb 3 5)))]
comb :: num->num->[[num]]
comb m n = comb' m [0..n-1]
where comb' 0 xs = [[]]
comb' m [] = []
comb' m (x:xs) = map (x:) (comb' (m-1) xs) ++ comb' m xs