<<< native
[ EArray
    [ AlignCenter , AlignCenter ]
    [ [ [ EIdentifier "H" ] , [ EIdentifier "A" ] ]
    , [ [ EIdentifier "T" ] , [ EIdentifier "I" ] ]
    , [ [ EIdentifier "U" ] , [ EIdentifier "Y" ] ]
    ]
, ESymbol Rel "="
, EArray
    [ AlignCenter , AlignCenter ]
    [ [ [ EIdentifier "A" ] , [ EIdentifier "H" ] ]
    , [ [ EIdentifier "I" ] , [ EIdentifier "T" ] ]
    , [ [ EIdentifier "Y" ] , [ EIdentifier "U" ] ]
    ]
]
>>> tex
\begin{matrix}
H & A \\
T & I \\
U & Y
\end{matrix} = \begin{matrix}
A & H \\
I & T \\
Y & U
\end{matrix}