(def ps7
  (bind n 0
    (bind add-twice (abs x
                      (begin (<- x (* 2 x))
                             (<- n (+ n x))
                             n))
      (bind test (abs z
                   (+ (* 100 (add-twice n))
                      (+ (* 10 z) z)))
        (test (add-twice 1))))))
