Since {HEAD ~ the achievement} of {TAIL ~ coherency} is distributed in time and space, the node controller helps to maintain cache coherency 
of
Since { HEAD ~ the achievement } of { TAIL ~ coherency } is distributed in time and space , the node controller helps to maintain cache coherency
OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH