title: How to XPATH select a list of Uncles
body: <p>Im kind of new to xpath, so... sorry in advance if something is not referred to accurately...
  I would like to formulate an xpath query which will select the 'uncle' of each element of a specific name:</p>
  <p>Say I have the following XML:</p>
  <pre><code>    &lt;aaa&gt;
          &lt;bbb&gt;
              &lt;first_uncle&gt;
                  uncle_bob
              &lt;/first_uncle&gt;
              &lt;ccc&gt;
                  &lt;ddd&gt;d_val_1&lt;/ddd&gt;
              &lt;/ccc&gt;
              &lt;ccc&gt;
                  &lt;ddd&gt;d_val_2&lt;/ddd&gt;
              &lt;/ccc&gt;
              &lt;ccc&gt;
                  &lt;ddd&gt;d_val_3&lt;/ddd&gt;
              &lt;/ccc&gt;
         &lt;/bbb&gt;
          &lt;bbb&gt;
              &lt;first_uncle&gt;
                  uncle_jack
              &lt;/first_uncle&gt;
              &lt;ccc&gt;
                  &lt;ddd&gt;d_val_4&lt;/ddd&gt;
              &lt;/ccc&gt;
              &lt;ccc&gt;
                  &lt;ddd&gt;d_val_5&lt;/ddd&gt;
              &lt;/ccc&gt;
         &lt;/bbb&gt;
     &lt;/aaa&gt;
  </code></pre>
  <p>I would like to have an output which lists the 'first_uncle' of each <code>ddd</code>.
  Something like this:</p>
  <pre><code>uncle_bob
  uncle_bob
  uncle_bob
  uncle_jack
  uncle_jack
  </code></pre>
  <p>My trials (<code>//ccc/ddd/../../*[1]</code>) gave me a list of 'unique uncles':</p>
  <pre><code>uncle_bob
  uncle_jack
  </code></pre>
  <p>Thanks!</p>