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Matching data using patterns

A simple query to select those authors that have published for Addison-Wesley:
  WHERE <bib><book>
          <publisher><name>"Addison-Wesley"</name></publisher>
          <title>  $t </title>
          <author> $a </author>
        </book></bib> IN "bib.xml"
  CONSTRUCT $a

A more convenient syntax is allowed:
  WHERE <bib><book>
          <publisher><name>"Addison-Wesley"</></>
          <title>  $t </>
          <author> $a </>
        </></> IN "bib.xml"
  CONSTRUCT $a

Note that XML-QL is not in XML syntax...