状態遷移図をSchemeに手作業変換。
deadlock
; [masaterukの日記](http://d.hatena.ne.jp/masateruk/20130813/1376398968)
; Definitions
(define-channel sch (x) '((0) (1)))
(define-channel rch (x) '((0) (1)))
; SYS
(define-process Sender
(! rch (0)
(? sch (x) (= x 0)
(! rch (1)
(? sch (x) (= x 1) Sender)))))
(define-process Receiver
(? rch (x) (= x 0)
(! sch (0)
(? rch (x) (= x 1)
(! sch (1) Receiver)))))
(define-process SYS
(par (list sch rch) Sender Receiver))