<<< native
[ ECancel
    ForwardSlash
    (EGrouped [ EIdentifier "a" , EIdentifier "b" , EIdentifier "c" ])
, EIdentifier "d"
, ESymbol Bin "+"
, ECancel BackSlash (ESuper (EIdentifier "x") (ENumber "2"))
, ESymbol Rel "="
, EIdentifier "d"
, ESymbol Bin "+"
, ECancel XSlash (ESuper (EIdentifier "x") (ENumber "2"))
]

>>> omml
<?xml version='1.0' ?>
<m:oMathPara>
  <m:oMathParaPr>
    <m:jc m:val="center" />
  </m:oMathParaPr>
  <m:oMath>
    <m:borderBox>
      <m:borderBoxPr>
        <m:hideTop m:val="1" />
        <m:hideBot m:val="1" />
        <m:hideLeft m:val="1" />
        <m:hideRight m:val="1" />
        <m:strikeBLTR m:val="1" />
      </m:borderBoxPr>
      <m:e>
        <m:r>
          <m:t>a</m:t>
        </m:r>
        <m:r>
          <m:t>b</m:t>
        </m:r>
        <m:r>
          <m:t>c</m:t>
        </m:r>
      </m:e>
    </m:borderBox>
    <m:r>
      <m:t>d</m:t>
    </m:r>
    <m:r>
      <m:rPr>
        <m:sty m:val="p" />
      </m:rPr>
      <m:t>+</m:t>
    </m:r>
    <m:borderBox>
      <m:borderBoxPr>
        <m:hideTop m:val="1" />
        <m:hideBot m:val="1" />
        <m:hideLeft m:val="1" />
        <m:hideRight m:val="1" />
        <m:strikeTLBR m:val="1" />
      </m:borderBoxPr>
      <m:e>
        <m:sSup>
          <m:e>
            <m:r>
              <m:t>x</m:t>
            </m:r>
          </m:e>
          <m:sup>
            <m:r>
              <m:t>2</m:t>
            </m:r>
          </m:sup>
        </m:sSup>
      </m:e>
    </m:borderBox>
    <m:r>
      <m:rPr>
        <m:sty m:val="p" />
      </m:rPr>
      <m:t>=</m:t>
    </m:r>
    <m:r>
      <m:t>d</m:t>
    </m:r>
    <m:r>
      <m:rPr>
        <m:sty m:val="p" />
      </m:rPr>
      <m:t>+</m:t>
    </m:r>
    <m:borderBox>
      <m:borderBoxPr>
        <m:hideTop m:val="1" />
        <m:hideBot m:val="1" />
        <m:hideLeft m:val="1" />
        <m:hideRight m:val="1" />
        <m:strikeBLTR m:val="1" />
        <m:strikeTLBR m:val="1" />
      </m:borderBoxPr>
      <m:e>
        <m:sSup>
          <m:e>
            <m:r>
              <m:t>x</m:t>
            </m:r>
          </m:e>
          <m:sup>
            <m:r>
              <m:t>2</m:t>
            </m:r>
          </m:sup>
        </m:sSup>
      </m:e>
    </m:borderBox>
  </m:oMath>
</m:oMathPara>