Its implied in a couple of exercises that map by default returns the same type as that of the collection it is passed. about clojurescript-koans

[lazerwalker]

That's a really good point. This was just ripped wholesale from the original Clojure Koans, but it's probably worth changing.

I suppose it makes the most sense to explicitly set up the sequence construct in the first exercise (e.g. (= (seq '(__)) (map (fn [x] (* 4 x)) [1 2 3])), and maybe in the equality section add an exercise that explicitly points out the comparability of vectors and sequences that allows the current exercise to work.