If the author is here, just a very minor nitpick: You could have done without the shadowing in the examples as that might be confusing to people not entirely awake or not familiar with Haskell.
Thank you for the feedback. I was conscientious of that shadowing issue when writing it, but I just wasn't sure what to change on either side to differentiate them.
Naming, the hardest problem in programming. I sympathize :)