<<< native
[ EDelimited
    "["
    "]"
    [ Right
        (EArray
           [ AlignCenter , AlignCenter ]
           [ [ [ EFraction
                   DisplayFrac
                   (EGrouped
                      [ ESymbol Ord "\8706" , ESub (EIdentifier "x") (ENumber "1") ])
                   (EGrouped
                      [ ESymbol Ord "\8706" , ESub (EIdentifier "y") (ENumber "1") ])
               ]
             , [ EFraction
                   DisplayFrac
                   (EGrouped
                      [ ESymbol Ord "\8706" , ESub (EIdentifier "x") (ENumber "2") ])
                   (EGrouped
                      [ ESymbol Ord "\8706" , ESub (EIdentifier "y") (ENumber "1") ])
               ]
             ]
           , [ [ ESpace (2 % 9) ] ]
           , [ [ EFraction
                   DisplayFrac
                   (EGrouped
                      [ ESymbol Ord "\8706" , ESub (EIdentifier "x") (ENumber "1") ])
                   (EGrouped
                      [ ESymbol Ord "\8706" , ESub (EIdentifier "y") (ENumber "2") ])
               ]
             , [ EFraction
                   DisplayFrac
                   (EGrouped
                      [ ESymbol Ord "\8706" , ESub (EIdentifier "x") (ENumber "2") ])
                   (EGrouped
                      [ ESymbol Ord "\8706" , ESub (EIdentifier "y") (ENumber "2") ])
               ]
             ]
           ])
    ]
, EDelimited
    "("
    ")"
    [ Right
        (EArray
           [ AlignCenter , AlignCenter ]
           [ [ [ ENumber "1" ] , [ ENumber "2" ] ]
           , [ [ ENumber "3" ] , [ ENumber "4" ] ]
           ])
    ]
, EDelimited
    "{"
    "}"
    [ Right
        (EArray
           [ AlignCenter , AlignCenter ]
           [ [ [ ENumber "1" ] , [ ENumber "2" ] ]
           , [ [ ENumber "3" ] , [ ENumber "4" ] ]
           ])
    ]
, EDelimited
    "\8739"
    "\8739"
    [ Right
        (EArray
           [ AlignCenter , AlignCenter ]
           [ [ [ ENumber "1" ] , [ ENumber "2" ] ]
           , [ [ ENumber "3" ] , [ ENumber "4" ] ]
           ])
    ]
, EDelimited
    "\8741"
    "\8741"
    [ Right
        (EArray
           [ AlignCenter , AlignCenter ]
           [ [ [ ENumber "1" ] , [ ENumber "2" ] ]
           , [ [ ENumber "3" ] , [ ENumber "4" ] ]
           ])
    ]
]
>>> eqn
left [ matrix{
ccol{ {{partial x sub 1} over {partial y sub 1}} above ~ above {{partial x sub 1} over {partial y sub 2}} }
ccol{ {{partial x sub 2} over {partial y sub 1}} above {{partial x sub 2} over {partial y sub 2}} }
} right ] left ( matrix{
ccol{ 1 above 3 }
ccol{ 2 above 4 }
} right ) left { matrix{
ccol{ 1 above 3 }
ccol{ 2 above 4 }
} right } left ∣ matrix{
ccol{ 1 above 3 }
ccol{ 2 above 4 }
} right ∣ left ∥ matrix{
ccol{ 1 above 3 }
ccol{ 2 above 4 }
} right ∥