data/pom/55.xml
<?xml version="1.0" ?>
<math type="pom-exported">
<expression prime-tag="sequence">
<term prime-tag="operator">\sum</term>
<expression prime-tag="underscore" secondary-tags="subscript_operation">
<term prime-tag="letter" secondary-tags="Latin">x</term>
</expression>
<term prime-tag="operator">\sum</term>
<expression prime-tag="underscore" secondary-tags="subscript_operation">
<term prime-tag="letter" secondary-tags="Latin">y</term>
</expression>
<term prime-tag="letter" secondary-tags="Latin">I</term>
<term prime-tag="left parenthesis" secondary-tags="opening delimiter">(</term>
<term prime-tag="letter" secondary-tags="Latin">x</term>
<term prime-tag="comma" secondary-tags="punctuation">,</term>
<term prime-tag="letter" secondary-tags="Latin">y</term>
<term prime-tag="right parenthesis" secondary-tags="closing delimiter">)</term>
</expression>
</math>