second differential amplifier means for generating {HEAD ~ an up down differential output signal} which is {TAIL ~ a function} of the difference in amplitude of said up and down output pulses; and 
is
second differential amplifier means for generating { HEAD ~ an up down differential output signal } which is { TAIL ~ a function } of the difference in amplitude of said up and down output pulses ; and
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH