A control part inspects {HEAD ~ the switch} to produce {TAIL ~ a condition signal} representative of one of the conditions to which the switch is switched 
to produce
A control part inspects { HEAD ~ the switch } to produce { TAIL ~ a condition signal } representative of one of the conditions to which the switch is switched
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH