title: WPF Binding: !value
body: <p>I have button:</p>
  
  <pre><code>&lt;Button Content="Stop loading" /&gt;
  </code></pre>
  
  <p>In ViewModel i have property IsLoaded. I don't want to write property IsNotLoaded but i want to use IsLoaded in binding and disable button when IsLoaded = true.</p>
  
  <p>How implement something like this:</p>
  
  <pre><code>&lt;Button Content="Stop loading" IsEnabled="{Binding !IsLoaded}" /&gt;
  </code></pre>
  
  <p>P.S. if it more difficult than writing of additional property, i will use IsNotLoaded property.</p>