D(node-metadata-equality-string,name:http://www.sleepycat.com/2002/dbxml,=,'sgml.xml',n(V(node-element-substring-string,title,substring,'is SGML'),P(edge-element-presence-none,prefix,section))) P(edge-element-presence-none,prefix,section) V(node-element-substring-string,title,substring,'is SGML')