stretchVert1.test

<<< native
[ EArray
    [ AlignCenter ]
    [ [ [ EGrouped
            [ EIdentifier "x"
            , ESymbol Bin "+"
            , EDelimited
                "("
                ")"
                [ Right (EFraction NormalFrac (ENumber "2") (ENumber "3")) ]
            ]
        ]
      ]
    , [ [ EDelimited
            ""
            ")"
            [ Right (EIdentifier "x")
            , Right (ESymbol Bin "+")
            , Right (EOver False (ESymbol Open "(") (ESymbol Bin "-"))
            , Right (EFraction NormalFrac (ENumber "2") (ENumber "3"))
            ]
        ]
      ]
    ]
]
>>> mml
<?xml version='1.0' ?>
<math display="block" xmlns="http://www.w3.org/1998/Math/MathML">
  <mtable>
    <mtr>
      <mtd columnalign="center" style="text-align: center">
        <mrow>
          <mi>x</mi>
          <mo>+</mo>
          <mrow>
            <mo stretchy="true" form="prefix">(</mo>
            <mfrac>
              <mn>2</mn>
              <mn>3</mn>
            </mfrac>
            <mo stretchy="true" form="postfix">)</mo>
          </mrow>
        </mrow>
      </mtd>
    </mtr>
    <mtr>
      <mtd columnalign="center" style="text-align: center">
        <mrow>
          <mi>x</mi>
          <mo>+</mo>
          <mover>
            <mo stretchy="false" form="prefix">(</mo>
            <mo accent="false">-</mo>
          </mover>
          <mfrac>
            <mn>2</mn>
            <mn>3</mn>
          </mfrac>
          <mo stretchy="true" form="postfix">)</mo>
        </mrow>
      </mtd>
    </mtr>
  </mtable>
</math>