{TAIL ~ The system} applies the transformed inexact query output to a heterogeneous datastore to provide {HEAD ~ an output query result} 
{ TAIL ~ The system } applies the transformed inexact query output to a heterogeneous datastore to provide { HEAD ~ an output query result }
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD