<<< native
[ EArray
    [ AlignCenter ]
    [ [ [ EGrouped
            [ EIdentifier "A"
            , ESymbol Bin "+"
            , EIdentifier "A"
            , ESymbol Bin "+"
            , EIdentifier "A"
            , ESymbol Bin "+"
            , EIdentifier "A"
            , ESymbol Bin "+"
            , EIdentifier "A"
            , ESymbol Bin "+"
            , EIdentifier "A"
            ]
        ]
      ]
    , [ [ EGrouped
            [ EStyled TextScript [ EIdentifier "A" ]
            , ESymbol Bin "+"
            , EIdentifier "A"
            , ESymbol Bin "+"
            , EIdentifier "A"
            , ESymbol Bin "+"
            , EIdentifier "A"
            ]
        ]
      ]
    , [ [ EGrouped
            [ EStyled TextScript [ EIdentifier "A" ]
            , ESymbol Bin "+"
            , EIdentifier "A"
            , ESymbol Bin "+"
            , EIdentifier "A"
            , ESymbol Bin "+"
            , EIdentifier "A"
            ]
        ]
      ]
    ]
]
>>> tex
\begin{matrix}
{A + A + A + A + A + A} \\
{\mathcal{A} + A + A + A} \\
{\mathcal{A} + A + A + A}
\end{matrix}