Process 2000 begins with operation 2002, where {HEAD ~ the reader} retrieves at least a TPK and {TAIL ~ an ES} from a tag 
retrieves
Process 2000 begins with operation 2002 , where { HEAD ~ the reader } retrieves at least a TPK and { TAIL ~ an ES } from a tag
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH