<<< native
[ EArray
    [ AlignCenter , AlignCenter , AlignCenter ]
    [ [ [ EGrouped
            [ EPhantom (EText TextNormal "F")
            , ESpace (0 % 1)
            , EIdentifier "HT"
            , ESpace (0 % 1)
            , EPhantom (EText TextNormal "F")
            ]
        ]
      , [ ESymbol Rel "=" ]
      , [ EIdentifier "TH" ]
      ]
    ]
]
>>> tex
\begin{matrix}
{\phantom{\text{F}}{HT}\phantom{\text{F}}} & = & {TH}
\end{matrix}