The conductor can be surrounded by additional layers of polymeric material as long as {HEAD ~ the outer layer} comprises {TAIL ~ the first polymeric material} 
The conductor can be surrounded by additional layers of polymeric material as long as { HEAD ~ the outer layer } comprises { TAIL ~ the first polymeric material }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL