1<result>
2  {
3    for $i in doc("items.xml")//item_tuple
4    where empty(doc("bids.xml")//bid_tuple[itemno = $i/itemno])
5    return
6        <no_bid_item>
7            { $i/itemno }
8            { $i/description }
9        </no_bid_item>
10  }
11</result>