The on off state of switch 56 is controlled by switching signals 57 coupled to {TAIL ~ a control terminal} 58 of {HEAD ~ switch} 56 
The on off state of switch 56 is controlled by switching signals 57 coupled to { TAIL ~ a control terminal } 58 of { HEAD ~ switch } 56
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD OTH