<<< mml $$\sqrt{\begin{array}{|c|}\hline \phantom{\mathrm{ABCD}}\\ \phantom{\mathrm{ABCD}}\\ \phantom{\mathrm{ABCD}}\\ \hline\end{array}}$$ >>> native [ ESqrt (EArray [ AlignCenter ] [ [ [ EPhantom (EIdentifier "ABCD") ] ] , [ [ EPhantom (EIdentifier "ABCD") ] ] , [ [ EPhantom (EIdentifier "ABCD") ] ] ]) ]