252.test

<<< mml
<math display="block">
  <mmultiscripts>
    <mi>X</mi> <!-- base expression -->
    <mn>1</mn> <!-- post-sub-script-1 -->
    <mn>2</mn> <!-- post-sup-script-1 -->
    <mn>3</mn> <!-- post-sub-script-2 -->
    <mn>4</mn> <!-- post-sup-script-2 -->
    <mprescripts />
    <mn>5</mn> <!-- pre-sub-script-1 -->
    <mn>6</mn> <!-- pre-sup-script-1 -->
    <mn>7</mn> <!-- pre-sub-script-2 -->
    <mn>8</mn> <!-- pre-sup-script-2 -->
  </mmultiscripts>
  <mmultiscripts>
    <mi>X</mi> <!-- base expression -->
    <mn>1</mn> <!-- post-sub-script -->
    <mn>4</mn> <!-- post-sup-script -->
    <mprescripts />
    <mn>8</mn> <!-- pre-sub-script -->
  </mmultiscripts>
  <mmultiscripts>
    <mi>X</mi> <!-- base expression -->
    <none/>
    <mn>4</mn> <!-- post-sup-script -->
    <mprescripts />
    <mn>8</mn> <!-- pre-sub-script -->
  </mmultiscripts>
  <mmultiscripts>
    <mi>X</mi> <!-- base expression -->
    <mn>1</mn> <!-- post-sub-script -->
  </mmultiscripts>
  <MMULTISCRIPTS>
  <MROW><MI>F</MI></MROW>
  <MROW><MN>2</MN></MROW>
  <NONE>
  </NONE>
  <MPRESCRIPTS></MPRESCRIPTS>
  <MROW><MN>3</MN></MROW>
  <NONE>
  </NONE>
  </MMULTISCRIPTS>
</math>
>>> native
[ EGrouped
    [ ESubsup
        (EGrouped [])
        (EGrouped [ ENumber "5" , ENumber "7" ])
        (EGrouped [ ENumber "6" , ENumber "8" ])
    , ESubsup
        (EIdentifier "X")
        (EGrouped [ ENumber "1" , ENumber "3" ])
        (EGrouped [ ENumber "2" , ENumber "4" ])
    ]
, EGrouped
    [ ESub (EGrouped []) (ENumber "8")
    , ESubsup (EIdentifier "X") (ENumber "1") (ENumber "4")
    ]
, EGrouped
    [ ESub (EGrouped []) (ENumber "8")
    , ESubsup (EIdentifier "X") (EGrouped []) (ENumber "4")
    ]
, ESub (EIdentifier "X") (ENumber "1")
, EGrouped
    [ ESubsup (EGrouped []) (ENumber "3") (EGrouped [])
    , ESubsup (EIdentifier "F") (ENumber "2") (EGrouped [])
    ]
]