{HEAD ~ A second transistor} couples at least one logic input of {TAIL ~ the logic circuit} to the input of the amplifier 
{ HEAD ~ A second transistor } couples at least one logic input of { TAIL ~ the logic circuit } to the input of the amplifier
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH