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