<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML">
<mml:mfenced close="}" open="{"> <mml:mfenced close="|" open="|"> <mml:msubsup> <mml:mi>d</mml:mi>
<mml:mi>q</mml:mi>
<mml:mi>b</mml:mi>
</mml:msubsup>
</mml:mfenced>
</mml:mfenced>
</mml:math>