Pythagoras' theorem using J's under idiom in Clojure. See (http://mattyjwilliams.blogspot.com/2012/01/under-new-idiom-from-j-language.html)

pythag.clj

(defn under [verb, obverse, func x y]
  (obverse (func (verb x) (verb y))))

(defn sqrt [x]
  (Math/sqrt x))

(defn square [x]
  (Math/pow x 2))

(defn pythagoras [x y]
  (under square sqrt + x y))

(println (pythagoras 3 4))