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