title: XPath test to see if all the children's attributes have a certain value
body: <p>This is a simple XML file in which I want to do an XPath test:</p>
  
  <pre><code>&lt;Prop&gt;
      &lt;Attx&gt;
          &lt;Atty tip="ddd"&gt;&lt;/Atty&gt;
          &lt;Atty tip="ddd"&gt;&lt;/Atty&gt;
          &lt;Atty tip="ddd"&gt;&lt;/Atty&gt;
      &lt;/Attx&gt;   
  &lt;/Prop&gt;
  </code></pre>
  
  <p>I would like to see if <strong>all</strong> <code>tip</code> attributes of all the <code>Atty</code> elements equal <code>ddd</code>.</p>
  
  <p>I implemented this with the following XPath query:</p>
  
  <pre><code>count(/Prop/Attx/Atty[@tip='ddd'])=count(/Prop/Attx/Atty)
  </code></pre>
  
  <p>Is there a simpler query which can achieve the same test?</p>