texmath-0.13.1.2: test/writer/mml/mrootSscriptlevel4.test

<<< native
[ ERoot
    (EFraction NormalFrac (EIdentifier "x") (ENumber "3"))
    (EGrouped
       [ EIdentifier "x"
       , ESymbol Bin "-"
       , EFraction NormalFrac (EIdentifier "x") (ENumber "3")
       ])
, ESymbol Bin "+"
, ERoot
    (EFraction NormalFrac (EIdentifier "x") (ENumber "3"))
    (EGrouped [ EIdentifier "x" , ESymbol Bin "-" , ENumber "3" ])
, ESymbol Bin "+"
, ERoot
    (EFraction NormalFrac (EIdentifier "x") (ENumber "3"))
    (EGrouped [ EIdentifier "x" , ESymbol Bin "-" , ENumber "3" ])
, ESymbol Bin "+"
, EFraction NormalFrac (EIdentifier "x") (ENumber "3")
]
>>> mml
<?xml version='1.0' ?>
<math display="block" xmlns="http://www.w3.org/1998/Math/MathML">
  <mrow>
    <mroot>
      <mrow>
        <mi>x</mi>
        <mo>-</mo>
        <mfrac>
          <mi>x</mi>
          <mn>3</mn>
        </mfrac>
      </mrow>
      <mfrac>
        <mi>x</mi>
        <mn>3</mn>
      </mfrac>
    </mroot>
    <mo>+</mo>
    <mroot>
      <mrow>
        <mi>x</mi>
        <mo>-</mo>
        <mn>3</mn>
      </mrow>
      <mfrac>
        <mi>x</mi>
        <mn>3</mn>
      </mfrac>
    </mroot>
    <mo>+</mo>
    <mroot>
      <mrow>
        <mi>x</mi>
        <mo>-</mo>
        <mn>3</mn>
      </mrow>
      <mfrac>
        <mi>x</mi>
        <mn>3</mn>
      </mfrac>
    </mroot>
    <mo>+</mo>
    <mfrac>
      <mi>x</mi>
      <mn>3</mn>
    </mfrac>
  </mrow>
</math>