<html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Testcase</title> </head> <body onload="document.getElementById('B').appendChild(document.getElementById('A'));"> <div style="position: relative;"> <math xmlns="http://www.w3.org/1998/Math/MathML"> <mover> <mrow id="A"/> <mn id="B"/> </mover> </math> </div> </body> </html>