SICP Exercise 3.20

Exercise 3.20.  Draw environment diagrams to illustrate the evaluation of the sequence of expressions

(define x (cons 1 2))
(define z (cons x x))
(set-car! (cdr z) 17)
(car x)
17

using the procedural implementation of pairs given above. (Compare exercise 3.11.)

 Solution:

 The attached pictures show the progression of the environment structure as the sequence of interactions happens as specified in this exercise.

 The github links are:

 Page 1
Page 2
Page 3
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Page 5

The slides to the same diagrams are here

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