{HEAD ~ The operational amplifier} having the higher input potential will attempt to equalize {TAIL ~ its noninverting and inverting inputs} by reducing current through resistor R5, but will fail to do so, since the diode connected to the operational amplifier with the higher input signal will become reversed biased and turn off, thereby blocking the output of that operational amplifier 
{ HEAD ~ The operational amplifier } having the higher input potential will attempt to equalize { TAIL ~ its noninverting and inverting inputs } by reducing current through resistor R5 , but will fail to do so , since the diode connected to the operational amplifier with the higher input signal will become reversed biased and turn off , thereby blocking the output of that operational amplifier
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH