Otherwise, the present system applies {HEAD ~ additional candidate transformation rules} to {TAIL ~ the selected query element} to generate the transformed inexact query output for querying the heterogeneous datastore 
to
Otherwise , the present system applies { HEAD ~ additional candidate transformation rules } to { TAIL ~ the selected query element } to generate the transformed inexact query output for querying the heterogeneous datastore
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH