; here is a function that interleaves two streams and produces a new stream
(define (s-interleave s1 s2)
  (if (s-null? s1)
      s2
      (s-cons (s-first s1)
                   (s-interleave s2 (s-rest s1)))))

; here we enumerate the integers by interleaving the positive and negative ones
(define integers-bad
   (s-interleave naturals (s-map (lambda(x) (- x)) naturals)))

; when you display the first 12 terms of the stream you see it is not quite correct
; fix it
(s-interval-to-list integers 0 11)