{HEAD ~ The first and second electrodes} are formed of {TAIL ~ a conductive material} forming ohmic junction with the variable resistor and a conductive material forming non ohmic junction with the variable resistor, respectively 
are formed of
{ HEAD ~ The first and second electrodes } are formed of { TAIL ~ a conductive material } forming ohmic junction with the variable resistor and a conductive material forming non ohmic junction with the variable resistor , respectively
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL 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