<<< native
[ EArray
    [ AlignCenter , AlignCenter , AlignCenter , AlignCenter ]
    [ [ [ EText TextNormal "Top" ]
      , [ ENumber "3" ]
      , [ EFraction
            NormalFrac
            (EGrouped [ EIdentifier "a" , ESymbol Bin "+" , ENumber "1" ])
            (ENumber "2")
        ]
      , [ EOver
            False
            (EIdentifier "y")
            (EFraction
               NormalFrac
               (EGrouped [ EIdentifier "a" , ESymbol Bin "+" , ENumber "1" ])
               (ENumber "2"))
        ]
      ]
    , [ [ EText TextNormal "Bottom" ]
      , [ ENumber "3" ]
      , [ EFraction
            NormalFrac
            (EGrouped [ EIdentifier "a" , ESymbol Bin "+" , ENumber "1" ])
            (ENumber "2")
        ]
      , [ EOver
            False
            (EIdentifier "y")
            (EFraction
               NormalFrac
               (EGrouped [ EIdentifier "a" , ESymbol Bin "+" , ENumber "1" ])
               (ENumber "2"))
        ]
      ]
    , [ [ EText TextNormal "Center" ]
      , [ ENumber "3" ]
      , [ EFraction
            NormalFrac
            (EGrouped [ EIdentifier "a" , ESymbol Bin "+" , ENumber "1" ])
            (ENumber "2")
        ]
      , [ EOver
            False
            (EIdentifier "y")
            (EFraction
               NormalFrac
               (EGrouped [ EIdentifier "a" , ESymbol Bin "+" , ENumber "1" ])
               (ENumber "2"))
        ]
      ]
    , [ [ EText TextNormal "Baseline" ]
      , [ ENumber "3" ]
      , [ EFraction
            NormalFrac
            (EGrouped [ EIdentifier "a" , ESymbol Bin "+" , ENumber "1" ])
            (ENumber "2")
        ]
      , [ EOver
            False
            (EIdentifier "y")
            (EFraction
               NormalFrac
               (EGrouped [ EIdentifier "a" , ESymbol Bin "+" , ENumber "1" ])
               (ENumber "2"))
        ]
      ]
    ]
]
>>> eqn
matrix{
ccol{ {roman "Top"} above {roman "Bottom"} above {roman "Center"} above {roman "Baseline"} }
ccol{ 3 above 3 above 3 above 3 }
ccol{ {{a + 1} over 2} above {{a + 1} over 2} above {{a + 1} over 2} above {{a + 1} over 2} }
ccol{ {y to {{a + 1} over 2}} above {y to {{a + 1} over 2}} above {y to {{a + 1} over 2}} above {y to {{a + 1} over 2}} }
}