하나의 점화식은 변하는 객체나 불변 스트림으로 나타날 수 있다.

(begin
  (define modulus 2147483647)
  (define multiplier 48271)
  (define (next-random seed)
    (remainder (* seed multiplier) modulus))
  (define (make-rand seed)
    (lambda ()
      (set! seed (next-random seed))
      seed))
  (define (random-stream seed)
    (let ((next (next-random seed)))
      (cons-stream next (random-stream next))))
  (define (take-stream stream count)
    (if (= count 0)
        '()
        (cons (car stream)
              (take-stream
                (force (cdr stream))
                (- count 1)))))
  (define (take-object generator count)
    (if (= count 0)
        '()
        (cons (generator)
              (take-object generator (- count 1)))))
  (define object-values
    (take-object (make-rand 1) 5))
  (define stream-values
    (take-stream (random-stream 1) 5))
  (list object-values
        stream-values
        (equal? object-values stream-values)))