<window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul" xmlns:html="http://www.w3.org/1999/xhtml" xmlns:mathml="http://www.w3.org/1998/Math/MathML">
<mathml:munder style="-moz-transform: translate(50px);clip-path: url(#h);"/>
</window>