<<< native
[ EArray
    [ AlignCenter ]
    [ [ [ EArray
            [ AlignCenter , AlignCenter ]
            [ [ [ ENumber "1" ] , [ ENumber "2" ] ]
            , [ [ EIdentifier "x" ] , [ EIdentifier "y" ] ]
            ]
        ]
      ]
    , [ [ EArray
            [ AlignCenter , AlignCenter ]
            [ [ [ ENumber "1" ] , [ ENumber "2" ] ]
            , [ [ EIdentifier "x" ] , [ EIdentifier "y" ] ]
            ]
        ]
      ]
    , [ [ EArray
            [ AlignCenter , AlignCenter ]
            [ [ [ ENumber "1" ] , [ ENumber "2" ] ]
            , [ [ EIdentifier "x" ] , [ EIdentifier "y" ] ]
            ]
        ]
      ]
    ]
]
>>> eqn
matrix{
ccol{ {matrix{
ccol{ 1 above x }
ccol{ 2 above y }
}} above {matrix{
ccol{ 1 above x }
ccol{ 2 above y }
}} above {matrix{
ccol{ 1 above x }
ccol{ 2 above y }
}} }
}