Loop and Recur

(doc loop)
(loop [x 1]
  (if (>= x 10) x
      (recur (+ 1 x))))
(loop [x '(1 2 6 7 3 8 9 0 1 3)
       total 0]
  (if (empty? x) total
    (recur (rest x) (+ total (first x)))))