When {TAIL ~ the test contactor} is in a test position, only one of {HEAD ~ the pair} of conductors is in contact with the test contact member 
When { TAIL ~ the test contactor } is in a test position , only one of { HEAD ~ the pair } of conductors is in contact with the test contact member
OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH