3 (define (stream-duplicates s)
4 (if (= (stream-car s) (stream-car (stream-cdr s)))
5 (cons-stream (stream-car s)
6 (stream-duplicates (stream-cdr s)))
7 (stream-duplicates (stream-cdr s))))
10 (+ (* i i i) (* j j j)))
12 (display-stream (stream-duplicates (stream-map (lambda (p)
13 (cube-sum (car p) (car (cdr p))))
14 (weighted-pairs integers integers cube-sum))))