title: NetLogo two agentsets operations
body: <p>I have two agentsets. Are there functions for finding:</p>
  
  <ol>
  <li>An agentset of agents that are present in both (intersection)</li>
  <li>An agentset of agents that are present in one and not the other</li>
  </ol>
  
  <p>I'm finding it very difficult to implement this by hand, especially when it's needed inside of a triple <code>ask</code></p>
  
  <p>Ideal use would be similar to <code>with</code> syntax:</p>
  
  <pre><code>let cross set1 and-in set2
  let uniq set1 with [color = red] not-in set2
  </code></pre>
  
  <p>Simple things like "Is agent A in the agentset X?" are problematic</p>