<html xmlns="http://www.w3.org/1999/xhtml"> <head> <script> function foo() { var mo = document.getElementById("mo"); mo.removeChild(mo.firstChild); } </script> </head> <body onload="foo();"> <div><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"> <mrow> <mi>x</mi> <mo id="mo">=</mo> <mi>y</mi> </mrow> </math></div> </body> </html>