1  Exercise 3.40.  Give all possible values of x that can result from executing
2 
3 (define x 10)
4 
5 (parallel-execute (lambda () (set! x (* x x)))
6                   (lambda () (set! x (* x x x))))
7 
8 Which of these possibilities remain if we instead use serialized procedures:
9 
10 (define x 10)
11 
12 (define s (make-serializer))
13 
14 (parallel-execute (s (lambda () (set! x (* x x))))
15                   (s (lambda () (set! x (* x x x)))))