{HEAD ~ A contact region} between {TAIL ~ the via} and the section of the metal layer may define a crossbar array 
between
{ HEAD ~ A contact region } between { TAIL ~ the via } and the section of the metal layer may define a crossbar array
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH