[instig007]

> In your example case: split the string into a list of words, that is tokenize based on spaces.

You've made a common mistake. You're wiring your listener's thinking with the imperative inside-out approach that you're used to. Instead, it should be explained as this: "strSum = sum . map read . words" is "a sum of all parsed values of the original input of space-separated words". The reason you should avoid inside-out explanations is because in Haskell you're allowed to move from general ideas to specifics, and you can sprinkle `undefined` and `_` for specific details whilst thinking about general ideas and interfaces.