Exercise 3.40: Give all possible values of
x that can result from executing


(define x 10)
(parallel-execute 
 (lambda () (set! x (* x x)))
 (lambda () (set! x (* x x x))))

Which of these possibilities remain if we instead use serialized procedures:


(define x 10)
(define s (make-serializer))
(parallel-execute 
 (s (lambda () (set! x (* x x))))
 (s (lambda () (set! x (* x x x)))))