+(define (start-timer timer)
+ (timer 'start-timer))
+
+(define (stop-timer timer)
+ (timer 'stop-timer))
+
+(define (get-time timer)
+ (timer 'get-time))
+
+(define (get-state timer)
+ (timer 'get-state))
+
+(define (pause-timer timer)
+ (timer 'pause-timer))
+
+(define (resume-timer timer)
+ (timer 'resume-timer))