"SICP Exercise" 141 Exercise 3.72

Exercise 3-72 Original

Exercise 3.72. In a similar-to-exercise 3.71 generate a stream of all numbers so can be written as the sum of of the squares in three Different ways (showing how they can is so written).

Code

 (define (square x) (* x x))  (define (sum-square x) (+ (square (car x)  ) (square (cadr x) )))  (Define (squaresn s)          (define (stream-cadr s) (stream-car (stream-cdr s)) )          (define (stream-caddr s) (stream-cadr (stream-cdr s )))          ( Let ((scar (stream-car s))(scadr (stream-cadr s) )(scaddr (stream-caddr s)))                                                          (if (= (sum-square Scar) (sum-square scadr) (  Sum-square scaddr))                          (cons-stream (list (sum-square scar) scar Scadr scaddr)(  SQUARESN (stream-cdr (stream-cdr (stream-cdr s))) ))                           (squaresn (stream-cdr s)))))  (define square-numbers (squaresn (weighted-pairs integers integers sum-sq Uare ))) 

"SICP Exercise" 141 Exercise 3.72