Chapter 1, Building Abstractions with Procedures
Section - Procedures and the Processes They Generate
Exercise 1.9
Process generated by the first procedure:
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; procedure
(define (+ a b)
(if (= a 0)
b
(inc (+ (dec a) b))))
; process generated
(+ 4 5)
(inc (+ 3 5))
(inc (inc (+ 2 5)))
(inc (inc (inc (+ 1 5))))
(inc (inc (inc (inc (+ 0 5)))))
(inc (inc (inc (inc 5))))
(inc (inc (inc 6)))
(inc (inc 7))
(inc 8)
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Process generated by second process:
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; procedure
(define (+ a b)
(if (= a 0)
b
(+ (dec a) (inc b))))
; process generated
(+ 4 5)
(+ 3 6)
(+ 2 7)
(+ 1 8)
(+ 0 9)
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Clearly first procedure generates recursive process and second generates iterative process.