{HEAD ~ The second driver circuit} drives {TAIL ~ a second load element} formed of the second material based on the second bias voltage 
{ HEAD ~ The second driver circuit } drives { TAIL ~ a second load element } formed of the second material based on the second bias voltage
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH