title: What is the correct way to check if two ISets have the same entities
body: <p>I wish to implement Equals for the following class where the order of Subs is not relevant</p>
  
  <pre><code>class Entity {
     ISet&lt;SubEntity&gt; Subs;
  }
  </code></pre>
  
  <p>This may be called in an inner loop comparing several thousand of entities, so performance may be an issue.</p>
  
  <p>From my cursory exploration I believe the best option is <code>other.Subs.ExclusiveOr(Subs).IsEmpty</code> . Is this correct?</p>