<<< native
[ EArray
    [ AlignCenter , AlignCenter , AlignCenter ]
    [ [ [ EFraction NormalFrac (EIdentifier "xxx") (EIdentifier "y") ]
      , [ EIdentifier "bbbb" ]
      , [ EIdentifier "c" ]
      ]
    , [ [ EFraction NormalFrac (EIdentifier "x") (EIdentifier "y") ]
      , [ EIdentifier "y" ]
      , [ EIdentifier "z" ]
      ]
    , [ [ EFraction NormalFrac (EIdentifier "x") (EIdentifier "y") ]
      , [ ENumber "2" ]
      , [ ENumber "333333" ]
      ]
    ]
]
>>> tex
\begin{matrix}
\frac{xxx}{y} & {bbbb} & c \\
\frac{x}{y} & y & z \\
\frac{x}{y} & 2 & 333333
\end{matrix}