title: XPATH - Select all child nodes with a specific attribute
body: <p>What would be the xpath query to find all child nodes with a specific attribute value, but starting from a node with a specific attribute value?</p>
  <p>This is kind of related to a question I posted earlier about parsing an rdf xml file - I thought I had solved it but not quite yet.</p>
  <p>For example, I am trying to parse and grab all of the <code>rdf:about</code> attribute values.  I have this working fine.  I need to add the following condition though - parsing needs to start after a specific <code>rdf:about</code> value is found.</p>
  <p>I am working in PHP and and using <code>DomDocument</code> and am using the following xpath query:</p>
  <pre><code>$xpath-&gt;query('//@rdf:about');
  </code></pre>
  <p>It is finding all <code>rdf:about</code> attributes fine.</p>
  <p>I need to extend this to only find those attributes that come after the node whose <code>rdf:about</code> attribute is equal to something.</p>
  <p>How?</p>