The process 52 wherein each of the parallel processing elements generates {HEAD ~ an intermediate result} for {TAIL ~ its respective partition} 
The process 52 wherein each of the parallel processing elements generates { HEAD ~ an intermediate result } for { TAIL ~ its respective partition }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL