[Haskell-cafe] Newbie question: the need for parentheses

Hi, I have this function that sums up a list of numbers: suma [] = 0 suma (h:t) = h + suma t However, why do I need the parenthes in the second clause? What does the compiler think I'm trying to do when I type suma [] = 0 suma h:t = h + suma t Thanks! :-)