; Recursive version of accumulate
(define (accumulate a b combiner null-value term next)
	(if (> a b)
		null-value
		(combiner (term a)
			  (accumulate (next a) b combiner null-value term next))))
 
; Iterative version of accumulate
(define (accumulate-iter a b combiner null-value term next)
		(define (iter a result)
			(if (> a b)
				result
				(iter (next a) (combiner result
							 (term a)))))
		(iter a null-value))
 
; implementation of sum func using accumulate
; (recursive accumulate)
(define (sum a b)
	(accumulate a b + 0 (lambda (x) (x)) 
		     	    (lambda (x) (+ x 1))))
 
; implementation of product func using accumulate
; (iterative accumulate)
(define (product a b)
	(accumulate-iter a b * 1 (lambda (x) (x))
			  	 (lambda (x) (+ x 1))))
 
; sum all naturals in [1..10] (recursive accumulate)
(sum 1 10)
(newline)
 
; multiply all naturals in [1..10] (recursive accumulate)
(product 1 10)
(newline)
 

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