An amplifying circuit amplifies and outputs {HEAD ~ voltage difference} between first external input voltage and voltage corresponding to {TAIL ~ second external input voltage} 
An amplifying circuit amplifies and outputs { HEAD ~ voltage difference } between first external input voltage and voltage corresponding to { TAIL ~ second external input voltage }
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL