<!DOCTYPE html> <html class="reftest-wait"> <head> <title>mfrac childnode update</title> <script type="text/javascript"> function doTest() { var x = document.getElementById("innerMfrac"); var y = document.createElementNS("http://www.w3.org/1998/Math/MathML","mi"); var z = document.createElementNS("http://www.w3.org/1998/Math/MathML","mi"); y.innerHTML = "c"; z.innerHTML = "d"; x.appendChild(y); x.appendChild(z); document.documentElement.removeAttribute("class"); } window.addEventListener("MozReftestInvalidate",doTest, false); </script> </head> <body> <math> <mfrac style="font-size: 300%"> <mfrac> <mi> a </mi> <mi> b </mi> </mfrac> <mfrac id="innerMfrac"> </mfrac> </mfrac> </math> </body> </html>