pandoc/test/command/5708.md

```
% pandoc -f rst -t native
+--------+----------------+
| 123456 | :math:`a + b`  |
+--------+----------------+
^D
[ Table
  ( "", [], [] )
  ( Caption Nothing [] )
  [
    ( AlignDefault, ColWidth 0.125 )
  ,
    ( AlignDefault, ColWidth 0.2361111111111111 )
  ]
  ( TableHead ( "", [], [] ) [] )
  [ TableBody
    ( "", [], [] )
    ( RowHeadColumns 0 ) []
    [ Row
      ( "", [], [] )
      [ Cell
        ( "", [], [] ) AlignDefault
        ( RowSpan 1 )
        ( ColSpan 1 )
        [ Plain [ Str "123456" ] ]
      , Cell
        ( "", [], [] ) AlignDefault
        ( RowSpan 1 )
        ( ColSpan 1 )
        [ Plain [ Math InlineMath "a + b" ] ]
      ]
    ]
  ]
  ( TableFoot ( "", [], [] ) [] )
]
```