SICP Exercise 1.30 Sum-Iterative

Exercise 1.30.  The sum procedure above generates a linear recursion. The procedure can be rewritten so that the sum is performed iteratively. Show how to do this by filling in the missing expressions in the following definition:



(define (sum term a next b)
  (define (iter a result)
    (if <??>
        <??>
        (iter <??> <??>)))
  (iter <??> <??>))

 SOLUTION

 The code and tests are here.

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