<<< native
[ EArray
    [ AlignLeft , AlignLeft , AlignLeft ]
    [ [ [ ENumber "1" ]
      , [ EGrouped
            [ EIdentifier "x" , ESymbol Bin "+" , EIdentifier "y" ]
        ]
      , [ EGrouped
            [ ESuper (EIdentifier "x") (ENumber "2")
            , ESymbol Bin "+"
            , EGrouped
                [ ENumber "2"
                , ESymbol Ord "\8290"
                , EIdentifier "y"
                , ESymbol Ord "\8290"
                , EIdentifier "x"
                ]
            , ESymbol Bin "+"
            , ESuper (EIdentifier "y") (ENumber "2")
            ]
        ]
      ]
    , [ [ EGrouped
            [ EIdentifier "x" , ESymbol Bin "+" , EIdentifier "y" ]
        ]
      , [ EGrouped
            [ ESuper (EIdentifier "x") (ENumber "2")
            , ESymbol Bin "+"
            , EGrouped
                [ ENumber "2"
                , ESymbol Ord "\8290"
                , EIdentifier "y"
                , ESymbol Ord "\8290"
                , EIdentifier "x"
                ]
            , ESymbol Bin "+"
            , ESuper (EIdentifier "y") (ENumber "2")
            ]
        ]
      , [ EGrouped
            [ ESuper (EIdentifier "x") (ENumber "3")
            , ESymbol Bin "+"
            , EGrouped
                [ ENumber "3"
                , ESymbol Ord "\8290"
                , EIdentifier "y"
                , ESymbol Ord "\8290"
                , ESuper (EIdentifier "x") (ENumber "2")
                ]
            , ESymbol Bin "+"
            , EGrouped
                [ ENumber "3"
                , ESymbol Ord "\8290"
                , ESuper (EIdentifier "y") (ENumber "2")
                , ESymbol Ord "\8290"
                , EIdentifier "x"
                ]
            , ESymbol Bin "+"
            , ESuper (EIdentifier "y") (ENumber "3")
            ]
        ]
      ]
    , [ [ EGrouped
            [ ESuper (EIdentifier "x") (ENumber "2")
            , ESymbol Bin "+"
            , EGrouped
                [ ENumber "2"
                , ESymbol Ord "\8290"
                , EIdentifier "y"
                , ESymbol Ord "\8290"
                , EIdentifier "x"
                ]
            , ESymbol Bin "+"
            , ESuper (EIdentifier "y") (ENumber "2")
            ]
        ]
      , [ EGrouped
            [ ESuper (EIdentifier "x") (ENumber "3")
            , ESymbol Bin "+"
            , EGrouped
                [ ENumber "3"
                , ESymbol Ord "\8290"
                , EIdentifier "y"
                , ESymbol Ord "\8290"
                , ESuper (EIdentifier "x") (ENumber "2")
                ]
            , ESymbol Bin "+"
            , EGrouped
                [ ENumber "3"
                , ESymbol Ord "\8290"
                , ESuper (EIdentifier "y") (ENumber "2")
                , ESymbol Ord "\8290"
                , EIdentifier "x"
                ]
            , ESymbol Bin "+"
            , ESuper (EIdentifier "y") (ENumber "3")
            ]
        ]
      , [ EGrouped
            [ ESuper (EIdentifier "x") (ENumber "4")
            , ESymbol Bin "+"
            , EGrouped
                [ ENumber "4"
                , ESymbol Ord "\8290"
                , EIdentifier "y"
                , ESymbol Ord "\8290"
                , ESuper (EIdentifier "x") (ENumber "3")
                ]
            , ESymbol Bin "+"
            , EGrouped
                [ ENumber "6"
                , ESymbol Ord "\8290"
                , ESuper (EIdentifier "y") (ENumber "2")
                , ESymbol Ord "\8290"
                , ESuper (EIdentifier "x") (ENumber "2")
                ]
            , ESymbol Bin "+"
            , EGrouped
                [ ENumber "4"
                , ESymbol Ord "\8290"
                , ESuper (EIdentifier "y") (ENumber "3")
                , ESymbol Ord "\8290"
                , EIdentifier "x"
                ]
            , ESymbol Bin "+"
            , ESuper (EIdentifier "y") (ENumber "4")
            ]
        ]
      ]
    , [ [ EGrouped
            [ ESuper (EIdentifier "x") (ENumber "3")
            , ESymbol Bin "+"
            , EGrouped
                [ ENumber "3"
                , ESymbol Ord "\8290"
                , EIdentifier "y"
                , ESymbol Ord "\8290"
                , ESuper (EIdentifier "x") (ENumber "2")
                ]
            , ESymbol Bin "+"
            , EGrouped
                [ ENumber "3"
                , ESymbol Ord "\8290"
                , ESuper (EIdentifier "y") (ENumber "2")
                , ESymbol Ord "\8290"
                , EIdentifier "x"
                ]
            , ESymbol Bin "+"
            , ESuper (EIdentifier "y") (ENumber "3")
            ]
        ]
      , [ EGrouped
            [ ESuper (EIdentifier "x") (ENumber "4")
            , ESymbol Bin "+"
            , EGrouped
                [ ENumber "4"
                , ESymbol Ord "\8290"
                , EIdentifier "y"
                , ESymbol Ord "\8290"
                , ESuper (EIdentifier "x") (ENumber "3")
                ]
            , ESymbol Bin "+"
            , EGrouped
                [ ENumber "6"
                , ESymbol Ord "\8290"
                , ESuper (EIdentifier "y") (ENumber "2")
                , ESymbol Ord "\8290"
                , ESuper (EIdentifier "x") (ENumber "2")
                ]
            , ESymbol Bin "+"
            , EGrouped
                [ ENumber "4"
                , ESymbol Ord "\8290"
                , ESuper (EIdentifier "y") (ENumber "3")
                , ESymbol Ord "\8290"
                , EIdentifier "x"
                ]
            , ESymbol Bin "+"
            , ESuper (EIdentifier "y") (ENumber "4")
            ]
        ]
      , [ EGrouped
            [ ESuper (EIdentifier "x") (ENumber "5")
            , ESymbol Bin "+"
            , EGrouped
                [ ENumber "5"
                , ESymbol Ord "\8290"
                , EIdentifier "y"
                , ESymbol Ord "\8290"
                , ESuper (EIdentifier "x") (ENumber "4")
                ]
            , ESymbol Bin "+"
            , EGrouped
                [ ENumber "10"
                , ESymbol Ord "\8290"
                , ESuper (EIdentifier "y") (ENumber "2")
                , ESymbol Ord "\8290"
                , ESuper (EIdentifier "x") (ENumber "3")
                ]
            , ESymbol Bin "+"
            , EGrouped
                [ ENumber "10"
                , ESymbol Ord "\8290"
                , ESuper (EIdentifier "y") (ENumber "3")
                , ESymbol Ord "\8290"
                , ESuper (EIdentifier "x") (ENumber "2")
                ]
            , ESymbol Bin "+"
            , EGrouped
                [ ENumber "5"
                , ESymbol Ord "\8290"
                , ESuper (EIdentifier "y") (ENumber "4")
                , ESymbol Ord "\8290"
                , EIdentifier "x"
                ]
            , ESymbol Bin "+"
            , ESuper (EIdentifier "y") (ENumber "5")
            ]
        ]
      ]
    ]
]
>>> tex
\begin{array}{lll}
1 & {x + y} & {x^{2} + {2yx} + y^{2}} \\
{x + y} & {x^{2} + {2yx} + y^{2}} & {x^{3} + {3yx^{2}} + {3y^{2}x} + y^{3}} \\
{x^{2} + {2yx} + y^{2}} & {x^{3} + {3yx^{2}} + {3y^{2}x} + y^{3}} & {x^{4} + {4yx^{3}} + {6y^{2}x^{2}} + {4y^{3}x} + y^{4}} \\
{x^{3} + {3yx^{2}} + {3y^{2}x} + y^{3}} & {x^{4} + {4yx^{3}} + {6y^{2}x^{2}} + {4y^{3}x} + y^{4}} & {x^{5} + {5yx^{4}} + {10y^{2}x^{3}} + {10y^{3}x^{2}} + {5y^{4}x} + y^{5}}
\end{array}