Once the minimum number of index entries is determined a grid can be partitioned into the appropriate number of {HEAD ~ grid cells} to support {TAIL ~ efficient grid indexing} 
to support
Once the minimum number of index entries is determined a grid can be partitioned into the appropriate number of { HEAD ~ grid cells } to support { TAIL ~ efficient grid indexing }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL