Axiomatic Specifications:VDM Clock - 2

SETALARMTIME(new_time: N)

ext wr alarm_time: N, bell: {quiet, ringing}

rd time: N, alarm: {disabled, enabled}

pre true

post (alarm_time????new_time) ? (if (alarm_time? = time?) ? (alarm? = enabled)then (bell? = ringing) else (bell? = bell)

ENABLEALARM()

ext wr alarm: {disabled, enabled}, bell: {quiet, ringing}

rd time: N, alarm_time: N

pre alarm = disabled

post (alarm? = enabled) ? (if (alarm_time? = time?) then (bell? = ringing) else (bell? = bell)

DISABLEALARM()

ext wr alarm: {disabled, enabled}, bell: {quiet, ringing}

pre alarm = enabled

post (alarm? = disabled) ? (bell? = quiet)

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