ct</code>, <code>MutableProperty</code>, <code>Variable</code>) from reactive frameworks. This abstraction uses concept similar to type-erasure or protocol witness pattern, wrapping the behaviour of concrete implementations and delegating to them once the wrapper funcions are called.
    </div>
  </div>
  
  <!-- The sidebar once we have one: <div class="summary"></div> -->
  
  <div class="primary-content">
    <section id='declaration' class='declaration'>
  <h2>Declaration</h2>
  <div class='declaration-