12.test

<<< 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" ]
             ]
           ])
    ]
]
>>> mml
<?xml version='1.0' ?>
<math display="block" xmlns="http://www.w3.org/1998/Math/MathML">
  <mrow>
    <mi>f</mi>
    <mrow>
      <mo stretchy="true" form="prefix">(</mo>
      <mi>x</mi>
      <mo stretchy="true" form="postfix">)</mo>
    </mrow>
    <mo>=</mo>
    <mrow>
      <mo stretchy="true" form="prefix">{</mo>
      <mtable>
        <mtr>
          <mtd columnalign="left" style="text-align: left">
            <mn>1</mn>
          </mtd>
          <mtd columnalign="left" style="text-align: left">
            <mo>−</mo>
            <mn>1</mn>
            <mo>≤</mo>
            <mi>x</mi>
            <mo>&lt;</mo>
            <mn>0</mn>
          </mtd>
        </mtr>
        <mtr>
          <mtd columnalign="left" style="text-align: left">
            <mfrac>
              <mn>1</mn>
              <mn>2</mn>
            </mfrac>
          </mtd>
          <mtd columnalign="left" style="text-align: left">
            <mi>x</mi>
            <mo>=</mo>
            <mn>0</mn>
          </mtd>
        </mtr>
        <mtr>
          <mtd columnalign="left" style="text-align: left">
            <mn>1</mn>
            <mo>−</mo>
            <msup>
              <mi>x</mi>
              <mn>2</mn>
            </msup>
          </mtd>
          <mtd columnalign="left" style="text-align: left">
            <mtext mathvariant="normal">otherwise</mtext>
          </mtd>
        </mtr>
      </mtable>
    </mrow>
  </mrow>
</math>