The fail safe circuit also includes {HEAD ~ circuitry} for preventing inadvertent communication of the signal from the input terminal through the series switching network to the output terminal when one of the switching circuits is in a short circuited state or {TAIL ~ condition} 
The fail safe circuit also includes { HEAD ~ circuitry } for preventing inadvertent communication of the signal from the input terminal through the series switching network to the output terminal when one of the switching circuits is in a short circuited state or { TAIL ~ condition }
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL