Thereafter, the diode connected to the operational amplifier will remain off until the input to {HEAD ~ this amplifier} becomes approximately equal to or falls below the input to {TAIL ~ the operational amplifier} 
Thereafter , the diode connected to the operational amplifier will remain off until the input to { HEAD ~ this amplifier } becomes approximately equal to or falls below the input to { TAIL ~ the operational amplifier }
OTH OTH OTH OTH OTH OTH OTH 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 TAIL TAIL TAIL TAIL TAIL TAIL TAIL