{HEAD ~ The processing system} 1 then operates to extract {TAIL ~ content} from the data file, storing the content in the database 2 
operates to extract
{ HEAD ~ The processing system } 1 then operates to extract { TAIL ~ content } from the data file , storing the content in the database 2
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH