Hi, I just started learning Haskell. But I have been having a problem with defining functions. For example,

diff :: Float-> Float

diff = if x>= y then x-y else y-x

<interactive>:1:29: parse error on input `='

It is rather weird as I have checked quite a few websites and this was supposed to work.

The same occurs when I try for guarded rules, except that it is now for |.

diff :: Float -> Float -> Float

diff x y | x >= y = x - y

| otherwise = y - x

<interactive>:1:42: parse error on input `|'

Please do help!

Thanks a lot.