1;;; -*-Scheme-*-
2
3(define acc)
4(define bcc)
5(define n 5)
6
7(define (a)
8  (if (not (= 0 (call-with-current-continuation
9		 (lambda (cc)
10		   (set! acc cc) 0))))
11      (if (> n 0)
12	  (begin
13	    (set! n (- n 1))
14	    (display "resume b") (newline)
15	    (bcc 1))
16	  #v)
17      acc))
18
19(define (b)
20  (if (not (= 0 (call-with-current-continuation
21		 (lambda (cc)
22		   (set! bcc cc) 0))))
23      (begin
24        (display "resume a") (newline)
25        (acc 1)))
26  bcc)
27
28(a)
29(b)
30(acc 1)
31