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