The <munder> MathML element is used to attach an accent or a limit under an expression. It uses the following syntax: <munder> base underscript </munder>
This element's attributes include the global MathML attributes as well as the following attribute:
accentunderA <boolean> indicating whether the under script should be treated as an accent (i.e., drawn bigger and closer to the base expression).
<math display="block">
<munder accentunder="true">
<mrow>
<mi>x</mi>
<mo>+</mo>
<mi>y</mi>
<mo>+</mo>
<mi>z</mi>
</mrow>
<mo>&#x23DF;<!--BOTTOM CURLY BRACKET--></mo>
</munder>
</math><mover> (Overscript)<munderover> (Underscript-overscript pair)