n(P(node-element-presence-none,=,item_id),V(edge-attribute-equality-string,order.@id,=,'4'),P(edge-element-presence-none,=,root:http://www.sleepycat.com/2002/dbxml.order)) P(edge-element-presence-none,=,root:http://www.sleepycat.com/2002/dbxml.order) P(node-element-presence-none,=,item_id)