gistfile1.clj

(defn cartp
  "cartesian product"
  ([] ())
  ([coll] (map list coll))
  ([coll & rest] (for [x coll y (apply cartp rest)] (conj y x))))

(defn closure-under? 
  [op vals check]
  (every? (fn [[a b]] (check (op a b))) (cartp vals vals)))

(defn a-associative?
  [op example-vals]
  (every? (fn [[a b c]] (= (op a (op b c)) (op (op a b) c)))
	  (cartp example-vals example-vals example-vals)))