For example, {HEAD ~ a metal layer} connects {TAIL ~ the two sub regions} of center region 34 
For example , { HEAD ~ a metal layer } connects { TAIL ~ the two sub regions } of center region 34
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH