Hello Does you find this version easier to understand? rangeProduct :: Int -> Int -> Int rangeProduct m n = if m > n then 0 else if m == n then m else m * rangeProduct (m+1) n I would suspect the main point of the example is to make you think recursively - note how rangeProduct is called from within its own definition (on the last line of code). Before it, there are two stopping conditions that will halt recursion "if m > n " or "if m == n" - stopping conditions are crucial for recursive thinking and programming - without them you will recur endlessly and never produce an answer. If you exam is 'on paper' - that's to say code you can have some syntax errors because it isn't actually run - you want to be demonstrating that you can think recursively. Good luck Stephen