let $auction := doc("http://monetdb.cwi.nl/xmark/auctions.xml") return
for $a in $auction/site/closed_auctions/closed_auction
where
  not(
    empty(
      $a/annotation/description/parlist/listitem/parlist/listitem/text/emph/
       keyword/
       text()
    )
  )
return <person id="{$a/seller/@person}"/>