indexof (s:t, x, n) 
        | (x == s) = n
        | otherwise = indexof(t, x, n + 1)
indexof (s:t, x, n) 
        | (x == s) = n
        | otherwise = indexof(t, x, n + 1)
indexof (s:t, x, n) 
        | (x == s) = n
        | otherwise = indexof(t, x, n + 1)