title: See items that match in two list
body: <p>lest say I have two lists</p>
  
  <p>List1:</p>
  
  <p>"Tom",
  "Frank",
  "Lacey"</p>
  
  <p>List2:</p>
  
  <p>"Frank",
  "Tom"</p>
  
  <p>what would be the query needed to show that Tom and Fran are being repeated?</p>
  
  <p>The lists that I am trying to compare are very big and if I do something like:</p>
  
  <pre><code> var q = from a in List1
           from b in List2
           where a.Name == b.Name
           select a;
  </code></pre>
  
  <p>this takes a long time.</p>