{TAIL ~ A three dimensional crossbar array} may include a metal layer, and {HEAD ~ an insulator layer} disposed adjacent the metal layer 
{ TAIL ~ A three dimensional crossbar array } may include a metal layer , and { HEAD ~ an insulator layer } disposed adjacent the metal layer
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH