<<< native
[ EFraction
    NormalFrac
    (EIdentifier "A")
    (EGrouped
       [ EIdentifier "B"
       , ESymbol Bin "+"
       , EFraction
           NormalFrac
           (EIdentifier "C")
           (EGrouped
              [ EIdentifier "D"
              , ESymbol Bin "+"
              , EFraction NormalFrac (EIdentifier "E") (EIdentifier "F")
              ])
       ])
, ESymbol Rel "="
, EFraction
    NormalFrac
    (EGrouped
       [ EPhantom (ENumber "1") , ESpace (0 % 1) , EIdentifier "A" ])
    (EGrouped
       [ EIdentifier "B"
       , ESymbol Bin "+"
       , EFraction
           NormalFrac
           (EIdentifier "C")
           (EGrouped
              [ EIdentifier "D"
              , ESymbol Bin "+"
              , EFraction
                  NormalFrac
                  (EIdentifier "E")
                  (EGrouped
                     [ EIdentifier "F" , ESpace (0 % 1) , EPhantom (ENumber "1") ])
              ])
       ])
]
>>> omml
<?xml version='1.0' ?>
<m:oMathPara>
  <m:oMathParaPr>
    <m:jc m:val="center" />
  </m:oMathParaPr>
  <m:oMath>
    <m:f>
      <m:fPr>
        <m:type m:val="bar" />
      </m:fPr>
      <m:num>
        <m:r>
          <m:t>A</m:t>
        </m:r>
      </m:num>
      <m:den>
        <m:r>
          <m:t>B</m:t>
        </m:r>
        <m:r>
          <m:rPr>
            <m:sty m:val="p" />
          </m:rPr>
          <m:t>+</m:t>
        </m:r>
        <m:f>
          <m:fPr>
            <m:type m:val="bar" />
          </m:fPr>
          <m:num>
            <m:r>
              <m:t>C</m:t>
            </m:r>
          </m:num>
          <m:den>
            <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:f>
              <m:fPr>
                <m:type m:val="bar" />
              </m:fPr>
              <m:num>
                <m:r>
                  <m:t>E</m:t>
                </m:r>
              </m:num>
              <m:den>
                <m:r>
                  <m:t>F</m:t>
                </m:r>
              </m:den>
            </m:f>
          </m:den>
        </m:f>
      </m:den>
    </m:f>
    <m:r>
      <m:rPr>
        <m:sty m:val="p" />
      </m:rPr>
      <m:t>=</m:t>
    </m:r>
    <m:f>
      <m:fPr>
        <m:type m:val="bar" />
      </m:fPr>
      <m:num>
        <m:phant>
          <m:phantPr>
            <m:show m:val="0" />
          </m:phantPr>
          <m:e>
            <m:r>
              <m:t>1</m:t>
            </m:r>
          </m:e>
        </m:phant>
        <m:r>
          <m:t>&#8203;</m:t>
        </m:r>
        <m:r>
          <m:t>A</m:t>
        </m:r>
      </m:num>
      <m:den>
        <m:r>
          <m:t>B</m:t>
        </m:r>
        <m:r>
          <m:rPr>
            <m:sty m:val="p" />
          </m:rPr>
          <m:t>+</m:t>
        </m:r>
        <m:f>
          <m:fPr>
            <m:type m:val="bar" />
          </m:fPr>
          <m:num>
            <m:r>
              <m:t>C</m:t>
            </m:r>
          </m:num>
          <m:den>
            <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:f>
              <m:fPr>
                <m:type m:val="bar" />
              </m:fPr>
              <m:num>
                <m:r>
                  <m:t>E</m:t>
                </m:r>
              </m:num>
              <m:den>
                <m:r>
                  <m:t>F</m:t>
                </m:r>
                <m:r>
                  <m:t>&#8203;</m:t>
                </m:r>
                <m:phant>
                  <m:phantPr>
                    <m:show m:val="0" />
                  </m:phantPr>
                  <m:e>
                    <m:r>
                      <m:t>1</m:t>
                    </m:r>
                  </m:e>
                </m:phant>
              </m:den>
            </m:f>
          </m:den>
        </m:f>
      </m:den>
    </m:f>
  </m:oMath>
</m:oMathPara>