{HEAD ~ a voltage regulator}, selectively enabled and disabled in response to a control input, {TAIL ~ a pair} of voltage monitors, 
{ HEAD ~ a voltage regulator } , selectively enabled and disabled in response to a control input , { TAIL ~ a pair } of voltage monitors ,
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH