title: RegExp exclusion, looking for a word not followed by another
body: <p>I am trying to search for all occurrences of "Tom" which are not followed by "Thumb".</p>
  
  <p>I have tried to look for </p>
  
  <pre><code>Tom ^((?!Thumb).)*$
  </code></pre>
  
  <p>but I still get the lines that match to Tom Thumb.</p>