<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<style type="text/css">

#q:after {
  content: 'A';
}

</style>
</head>
<body>

<mrow xmlns="http://www.w3.org/1998/Math/MathML"></mrow>
<span id="q"><span><div></div></span></span>

</body>
</html>