mfencedAdelims6.test

<<< native
[ EDelimited
    "["
    ")"
    [ Right
        (EGrouped [ EIdentifier "a" , ESymbol Bin "+" , EIdentifier "b" ])
    ]
, EDelimited
    "{"
    "}"
    [ Right (EFraction NormalFrac (EIdentifier "a") (EIdentifier "b"))
    , Left "|"
    , Right (EFraction NormalFrac (EIdentifier "d") (EIdentifier "e"))
    , Right (ESymbol Pun ";")
    , Right (EIdentifier "a")
    , Right (ESymbol Bin "+")
    , Right (EIdentifier "b")
    , Right (ESymbol Bin "+")
    , Right (EIdentifier "a")
    , Right (ESymbol Bin "+")
    , Right (EIdentifier "b")
    ]
]
>>> mml
<?xml version='1.0' ?>
<math display="block" xmlns="http://www.w3.org/1998/Math/MathML">
  <mrow>
    <mrow>
      <mo stretchy="true" form="prefix">[</mo>
      <mrow>
        <mi>a</mi>
        <mo>+</mo>
        <mi>b</mi>
      </mrow>
      <mo stretchy="true" form="postfix">)</mo>
    </mrow>
    <mrow>
      <mo stretchy="true" form="prefix">{</mo>
      <mfrac>
        <mi>a</mi>
        <mi>b</mi>
      </mfrac>
      <mo stretchy="true" form="infix">|</mo>
      <mfrac>
        <mi>d</mi>
        <mi>e</mi>
      </mfrac>
      <mo>;</mo>
      <mi>a</mi>
      <mo>+</mo>
      <mi>b</mi>
      <mo>+</mo>
      <mi>a</mi>
      <mo>+</mo>
      <mi>b</mi>
      <mo stretchy="true" form="postfix">}</mo>
    </mrow>
  </mrow>
</math>