<<< native
[ EArray
    [ AlignCenter ]
    [ [ [ EGrouped
            [ EIdentifier "x"
            , ESymbol Bin "-"
            , EFraction NormalFrac (EIdentifier "a") (EIdentifier "b")
            , EIdentifier "x"
            ]
        ]
      ]
    , [ [ EGrouped
            [ EIdentifier "x"
            , ESymbol Bin "-"
            , EFraction NormalFrac (ENumber "1") (EIdentifier "b")
            , EIdentifier "x"
            ]
        ]
      ]
    , [ [ EGrouped
            [ EIdentifier "x"
            , ESymbol Bin "-"
            , EFraction NormalFrac (ENumber "1") (ENumber "2")
            , EIdentifier "x"
            ]
        ]
      ]
    , [ [ EGrouped
            [ EIdentifier "x"
            , ESymbol Bin "-"
            , EFraction
                NormalFrac (ESuper (ENumber "1") (ENumber "2")) (EIdentifier "z")
            , EIdentifier "x"
            ]
        ]
      ]
    , [ [ EGrouped
            [ EIdentifier "x"
            , ESymbol Bin "-"
            , EFraction
                NormalFrac (EIdentifier "z") (ESuper (ENumber "1") (ENumber "2"))
            , EIdentifier "x"
            ]
        ]
      ]
    ]
]
>>> tex
\begin{matrix}
{x - \frac{a}{b}x} \\
{x - \frac{1}{b}x} \\
{x - \frac{1}{2}x} \\
{x - \frac{1^{2}}{z}x} \\
{x - \frac{z}{1^{2}}x}
\end{matrix}