1 <html xmlns=
"http://www.w3.org/1999/xhtml">
7 document
.getElementById("mtr").appendChild(document
.createTextNode("a"));
14 <div><math xmlns=
"http://www.w3.org/1998/Math/MathML" display=
"block">
15 <mrow>
<mfenced open=
"[" close=
"]">
<mtable>
<mtr id=
"mtr">
<mtd><mi>x
</mi></mtd>
<mtd><mi>y
</mi></mtd>
</mtr>
</mtable>
</mfenced>
</mrow>