4 (define (sum-odd-squares tree)
8 (if (odd? tree) (square tree) 0))
9 (else (+ (sum-odd-squares (car tree))
10 (sum-odd-squares (cdr tree))))))
18 (cons f (next (+ k 1)))
22 (define (filter pred? coll)
25 ((pred? (car coll)) (cons (car coll) (filter pred? (cdr coll))))
26 (else (filter pred? (cdr coll)))))
28 (define (accumulate op initial coll)
32 (accumulate op initial (cdr coll)))))
34 (define (enumerate-tree tree)
37 ((not (pair? tree)) (list tree))
38 (else (append (enumerate-tree (car tree))
39 (enumerate-tree (cdr tree))))))
41 (define (sum-odd-squares tree)
46 (enumerate-tree tree)))))
55 (define (list-fib-squares n)
62 (define (product-of-squares-of-odd-elements coll)