The Tor Browser / file revision

 <window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul" xmlns:mathml="http://www.w3.org/1998/Math/MathML">

 <box>

   <box style="background: initial;" id="f">

     <box style="margin-top: -9999999px;"/>

   </box>

   <mathml:divergence>

     <box/>

   </mathml:divergence>

   <mathml:moment command="f"/>

 </box>

 <script id="script" xmlns="http://www.w3.org/1999/xhtml"><![CDATA[

 function init() {

     var f = document.getElementsByTagName('mathml:divergence')[0];

     window.addEventListener('DOMAttrModified',function() { f.parentNode.removeChild(f);}, true);

     var x=document.getElementsByTagName('mathml:moment')[0];

     x.parentNode.removeChild(x);

 }

 window.addEventListener("load", init, false);

 ]]></script>

 </window>