title: Xpath query to select node when attribute does not exist?
body: <p>I want to select nodes for which a specific attribute does not exist. I've tried the Not() function, but it doesn't work. Is there a way for this?</p>
  
  <p>Example:
  The following Xpath query:</p>
  
  <pre><code>group/msg[not(@owner)]
  </code></pre>
  
  <p>Should retrieve the first node but not the 2nd one. However, both SketchPath (tool to test Xpath queries) and my C# code consider that the 2 nodes are ok.</p>
  
  <pre><code>&lt;group&gt;
      &lt;msg id="EVENTDATA_CCFLOADED_XMLCONTEXT"  numericId="14026"  translate="False"  topicId="302"  status="translated" &gt;
          &lt;text&gt;Context&lt;/text&gt;
          &lt;comment&gt;&lt;/comment&gt;
      &lt;/msg&gt;
      &lt;msg id="EVENTDATA_CCFLOADED_XMLCONTEXT_HELP"  numericId="14027"  translate="False"  topicId="302"  status="translated"  owner="EVENTDATA_CCFLOADED_XMLCONTEXT" &gt;
          &lt;text&gt;Provides the new data displayed in the Object.&lt;/text&gt;
          &lt;comment&gt;&lt;/comment&gt;
      &lt;/msg&gt;
  &lt;/group&gt;
  </code></pre>
  
  <hr>
  
  <p>In fact the Not() function works correctly, it's just that I had other conditions and parentheses weren't set correctly. <em>errare humanum est</em>.</p>