In particular, {TAIL ~ system} 301 may provide several grouping operators that analyze and consolidate {HEAD ~ data} from multiple streams 
In particular , { TAIL ~ system } 301 may provide several grouping operators that analyze and consolidate { HEAD ~ data } from multiple streams
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH