<<< native
[ ESuper
    (EDelimited
       "("
       ")"
       [ Right
           (EGrouped [ EIdentifier "x" , ESymbol Bin "+" , EIdentifier "y" ])
       ])
    (ENumber "2")
]
>>> omml
<?xml version='1.0' ?>
<m:oMathPara>
  <m:oMathParaPr>
    <m:jc m:val="center" />
  </m:oMathParaPr>
  <m:oMath>
    <m:sSup>
      <m:e>
        <m:d>
          <m:dPr>
            <m:begChr m:val="(" />
            <m:endChr m:val=")" />
            <m:sepChr m:val="" />
            <m:grow />
          </m:dPr>
          <m:e>
            <m:r>
              <m:t>x</m:t>
            </m:r>
            <m:r>
              <m:rPr>
                <m:sty m:val="p" />
              </m:rPr>
              <m:t>+</m:t>
            </m:r>
            <m:r>
              <m:t>y</m:t>
            </m:r>
          </m:e>
        </m:d>
      </m:e>
      <m:sup>
        <m:r>
          <m:t>2</m:t>
        </m:r>
      </m:sup>
    </m:sSup>
  </m:oMath>
</m:oMathPara>