<?xml version="1.0"?> <?xml-stylesheet href="chrome://global/skin" type="text/css"?> <window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul" xmlns:m="http://www.w3.org/1998/Math/MathML"> <script type="text/javascript"> <![CDATA[ function boom() { var e = document.getElementById("e"); var g = document.getElementById("maligngroup"); var M = "http://www.w3.org/1998/Math/MathML"; var a = document.createElementNS(M, "mfrac"); var b = document.createElementNS(M, "ms"); var c = document.createElementNS(M, "merror"); g.appendChild(c); a.appendChild(b); e.appendChild(a); } window.addEventListener("load", boom, false); ]]> </script> <m:math><box id="e"><m:mo><m:ms/><box style="display: inline;"><box><m:maligngroup id="maligngroup"/></box></box></m:mo></box></m:math> </window>