The MathML markup for this equation might be:
<semantics>
<mrow>
<msubsup>
<mo>∫</mo>
<mn>0</mn>
<mi>t</mi>
</msubsup>
<mfrac>
<mrow>
<mo>d</mo>
<mi>x</mi>
</mrow>
<mi>x</mi>
</mfrac>
</mrow>
<annotation-xml encoding="MathML-Content">
<apply>
<int/>
<bvar><ci>x</ci></bvar>
<lowlimit><cn>0</cn></lowlimit>
<uplimit><ci>t</ci></uplimit>
<apply>
<divide/>
<cn>1</cn>
<ci>x</ci>
</apply>
</apply>
</annotation-xml>
</semantics>Don't panic -- there will be programs that will generate this markup for you. For more about information (and the source of this example), see the W3C MathML Recommendation.
