When {TAIL ~ a signal} indicative of {HEAD ~ abnormal condition} is outputted from the sensing means, a signal processing circuit is actuated 
When { TAIL ~ a signal } indicative of { HEAD ~ abnormal condition } is outputted from the sensing means , a signal processing circuit is actuated
OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH