Haskell

Please help with my Haskell code. It is supposed to return the maximum element in a list but it doesn't work

lol :: [a] -> Nothing | a
lol [] = Nothing
lol [x] = x
lol (x:xs) = if x > lol xs then x else lol xs

>>26
Countless programs which will be stackoverflow'ed and run out of memory will make you think otherwise,
but for now you can read your newbie books and write it your way. Someday you might realize why your abstractions fail.