title: Regex how to match a substring that does not contain a fixed string. Regex in TexStudio:
body: <p>I want to a regex expression to replace the following string</p>
  
  <pre><code>{match1}{matchb}{not}{anotb}
  </code></pre>
  
  <p>with</p>
  
  <pre><code>match1matchb{not}{anotb}}
  </code></pre>
  
  <p>How to write the regex expression.</p>
  
  <p>Basically I want to find a string inside <code>{}</code> but the string can not contain <code>not</code>.</p>