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