<html xmlns="http://www.w3.org/1999/xhtml" class="reftest-wait"> <head> <script> var HTML_NS = "http://www.w3.org/1999/xhtml"; function boom() { var a = document.getElementById("a"); var plus = document.getElementById("plus"); var frameset = document.createElementNS(HTML_NS, "frameset"); document.body.style.width = "300px"; a.parentNode.removeChild(a); plus.appendChild(frameset); document.documentElement.removeAttribute("class"); } </script> </head> <body onload="setTimeout(boom, 30);"> <div><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"> <msup> <mi id="a">a</mi> <mo id="plus">+</mo> <mi>b</mi> <mi>c</mi> </msup> </math></div> </body> </html>