{-maxmin list = if null (tail list)
        then (head list, head list)
        else (  if (head list) > fst (maxmin (tail list))
            then head list
            else fst (maxmin (tail list))
             ,  if (head list) < snd (maxmin (tail list))
            then head list
            else snd (maxmin (tail list))
             )-}

maxmin list =   let h = head list
        in if null (tail list)
           then (h, h)
           else ( if h > t_max then h else t_max
            , if h < t_min then h else t_min)
            where t = maxmin (tail list)
                  t_max = fst t
                  t_min = snd t