(fn [f] (f 5)) I do love the format, but what I like a bit better about Clojure Koans is that you can see the previous ones for a bit of a reminder. Maybe for

(fn [f] (f 5)) I do love the format, but what I like a bit better about Clojure Koans is that you can see the previous ones for a bit of a reminder. Maybe for each section, they could leave up the ones you'd successfully completed so you could refer to them. Other than that minor nitpick, I love this.