<<< native
[ ESqrt
    (EArray
       [ AlignCenter , AlignCenter , AlignCenter ]
       [ [ [ EPhantom (EIdentifier "A") ]
         , [ EPhantom (EIdentifier "A") ]
         , [ EPhantom (EIdentifier "A") ]
         ]
       , [ [ EPhantom (EIdentifier "A") ]
         , [ EPhantom (EIdentifier "A") ]
         , [ EPhantom (EIdentifier "A") ]
         ]
       ])
]
>>> eqn
sqrt {matrix{
ccol{ {hphantom A} above {hphantom A} }
ccol{ {hphantom A} above {hphantom A} }
ccol{ {hphantom A} above {hphantom A} }
}}