<<< native
[ EIdentifier "f"
, EDelimited "(" ")" [ Right (EIdentifier "x") ]
, ESymbol Rel "="
, EDelimited
    "{"
    ""
    [ Right
        (EArray
           [ AlignLeft , AlignLeft ]
           [ [ [ ENumber "1" ]
             , [ ESymbol Bin "\8722"
               , ENumber "1"
               , ESymbol Rel "\8804"
               , EIdentifier "x"
               , ESymbol Rel "<"
               , ENumber "0"
               ]
             ]
           , [ [ EFraction NormalFrac (ENumber "1") (ENumber "2") ]
             , [ EIdentifier "x" , ESymbol Rel "=" , ENumber "0" ]
             ]
           , [ [ ENumber "1"
               , ESymbol Bin "\8722"
               , ESuper (EIdentifier "x") (ENumber "2")
               ]
             , [ EText TextNormal "otherwise" ]
             ]
           ])
    ]
]
>>> omml
<?xml version='1.0' ?>
<m:oMathPara>
  <m:oMathParaPr>
    <m:jc m:val="center" />
  </m:oMathParaPr>
  <m:oMath>
    <m:r>
      <m:t>f</m:t>
    </m:r>
    <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:e>
    </m:d>
    <m:r>
      <m:rPr>
        <m:sty m:val="p" />
      </m:rPr>
      <m:t>=</m:t>
    </m:r>
    <m:d>
      <m:dPr>
        <m:begChr m:val="{" />
        <m:endChr m:val="" />
        <m:sepChr m:val="" />
        <m:grow />
      </m:dPr>
      <m:e>
        <m:m>
          <m:mPr>
            <m:baseJc m:val="center" />
            <m:plcHide m:val="1" />
            <m:mcs>
              <m:mc>
                <m:mcPr>
                  <m:mcJc m:val="left" />
                  <m:count m:val="1" />
                </m:mcPr>
              </m:mc>
              <m:mc>
                <m:mcPr>
                  <m:mcJc m:val="left" />
                  <m:count m:val="1" />
                </m:mcPr>
              </m:mc>
            </m:mcs>
          </m:mPr>
          <m:mr>
            <m:e>
              <m:r>
                <m:t>1</m:t>
              </m:r>
            </m:e>
            <m:e>
              <m:r>
                <m:rPr>
                  <m:sty m:val="p" />
                </m:rPr>
                <m:t>−</m:t>
              </m:r>
              <m:r>
                <m:t>1</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>x</m:t>
              </m:r>
              <m:r>
                <m:rPr>
                  <m:sty m:val="p" />
                </m:rPr>
                <m:t>&lt;</m:t>
              </m:r>
              <m:r>
                <m:t>0</m:t>
              </m:r>
            </m:e>
          </m:mr>
          <m:mr>
            <m:e>
              <m:f>
                <m:fPr>
                  <m:type m:val="bar" />
                </m:fPr>
                <m:num>
                  <m:r>
                    <m:t>1</m:t>
                  </m:r>
                </m:num>
                <m:den>
                  <m:r>
                    <m:t>2</m:t>
                  </m:r>
                </m:den>
              </m:f>
            </m:e>
            <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>0</m:t>
              </m:r>
            </m:e>
          </m:mr>
          <m:mr>
            <m:e>
              <m:r>
                <m:t>1</m:t>
              </m:r>
              <m:r>
                <m:rPr>
                  <m:sty m:val="p" />
                </m:rPr>
                <m:t>−</m:t>
              </m:r>
              <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:e>
              <m:r>
                <m:rPr>
                  <m:nor />
                  <m:sty m:val="p" />
                </m:rPr>
                <m:t>otherwise</m:t>
              </m:r>
            </m:e>
          </m:mr>
        </m:m>
      </m:e>
    </m:d>
  </m:oMath>
</m:oMathPara>