Lazy seq of primes

gistfile1.clj

(defn mult?
  "Returns true iff n is a multiple of one of the numbers in coll."
  [coll n]
  (some #(zero? (rem n %)) coll))

(def primes
     (letfn [(rest-primes
	      [known-primes]
	      (lazy-seq
	       (let [highest-known-prime (peek known-primes),
		     next-prime
		     (first (drop-while
			     #(mult? known-primes %)
			     (iterate inc (inc highest-known-prime))))]
		 (cons highest-known-prime
		       (rest-primes (conj known-primes next-prime))))))]
       (rest-primes [2])))