title: PHP xpath contains class and does not contain class
body: <p>The title sums it up. I'm trying to query an HTML file for all div tags that contain the class <code>result</code> and does not contain the class <code>grid</code>.</p>
  
  <pre><code>&lt;div class="result grid"&gt;skip this div&lt;/div&gt;
  &lt;div class="result"&gt;grab this one&lt;/div&gt;
  </code></pre>
  
  <p>Thanks!</p>