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