<html xmlns="http://www.w3.org/1999/xhtml" xmlns:m="http://www.w3.org/1998/Math/MathML">
<head>
<script type="text/javascript">
function boom()
{
var m = document.getElementById("m");
m.parentNode.removeChild(m);
document.getElementById("s").appendChild(document.createTextNode("c"));
}
</script>
</head>
<body onload="boom();">
<m:mrow>
<span>
<m:msup id="m"/>
<div style="-moz-column-width: 1px;">
<m:munderover/>
<m:msqrt/>
</div>
</span>
<span id="s"></span>
</m:mrow>
</body>
</html>