title: XQuery/XPath "except" operation - Select part of sequence that is not in other sequence
body: <p>I have a pretty simple example but I am just learning and can't find a solution for the following:</p>
  
  <p>Given 2 sequences, being</p>
  
  <pre><code>&lt;emp&gt;10&lt;/emp&gt;
  &lt;emp&gt;42&lt;/emp&gt;
  &lt;emp&gt;100&lt;/emp&gt;
  </code></pre>
  
  <p>and another sequence</p>
  
  <pre><code>  &lt;emp&gt;10&lt;/emp&gt;
    &lt;emp&gt;42&lt;/emp&gt;
  </code></pre>
  
  <p>Want i want to do is: Compare the sequences and return the part of sequences that is in the first, but not in the 2nd sequence, being <code>&lt;emp&gt;100&lt;/emp&gt;</code> in this case.</p>
  
  <p>I was thinking about an "except"-operation, but can't figure out how to make it working.</p>
  
  <p>Help greatly appreciated.</p>