menclose-3-box-ref.html

Enable keyboard shortcuts

<!DOCTYPE html>

<html>

  <head>

    <title>menclose box</title>

    <meta charset="utf-8"/>

  </head>

  <body>

    <math>

      <menclose notation="left top right bottom">

        <mspace width="100px" height="50px" mathbackground="blue"></mspace>

      </menclose>

    </math>

  </body>

</html>