<html>
<head>
<script>

function boom()
{
  var MATHML_NS = "http://www.w3.org/1998/Math/MathML";

  var mtr = document.createElementNS(MATHML_NS, 'mtr');
  var mtable = document.createElementNS(MATHML_NS, 'mtable');

  document.body.appendChild(mtr);
  mtr.appendChild(mtable);
}

</script>
</head>

<body onload="boom()">

</body>
</html>
