D(node-metadata-equality-string,name:http://www.sleepycat.com/2002/dbxml,=,'items.xml',n(P(edge-element-equality-string,prefix,item_tuple.itemno),u(V(node-element-substring-string,description,substring,'Bicycle'),V(node-element-substring-string,description,substring,'Tricycle')))) V(node-element-substring-string,description,substring,'Bicycle') V(node-element-substring-string,description,substring,'Tricycle') D(node-metadata-equality-string,name:http://www.sleepycat.com/2002/dbxml,=,'bids.xml',V(edge-element-equality-string,bid_tuple.itemno,=,'[to be calculated]')) V(edge-element-equality-string,bid_tuple.itemno,=,'[to be calculated]') P(edge-element-equality-string,prefix,item_tuple.itemno)