stretchVert1.test

<<< mml
<?xml version="1.0" encoding="UTF-8"?>

<math xmlns="http://www.w3.org/1998/Math/MathML">
  <mstyle fontsize="130%" displaystyle="true">
    <mtable>
      <mtr>
        <mtd>
          <mrow>
            <mi>x</mi> 
            <mo>+</mo> 
              <mo>(</mo> 
            <mfrac>
              <mn>2</mn> 
              <mn>3</mn> 
            </mfrac> 
            <mo>)</mo> 
          </mrow> 
        </mtd> 
      </mtr> 
      <mtr>
        <mtd>
          <mrow>
            <mi>x</mi> 
            <mo>+</mo> 
              <mover>
                <mo>(</mo> 
                <mo>-</mo> 
              </mover> 
            <mfrac>
              <mn>2</mn> 
              <mn>3</mn> 
            </mfrac> 
            <mo>)</mo> 
          </mrow> 
        </mtd> 
      </mtr> 
    </mtable> 
  </mstyle> </math>

>>> 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"))
            ]
        ]
      ]
    ]
]