<<< tex
f(x) =
 \begin{cases}
 1 & -1 \le x < 0 \\
 \frac{1}{2} & x = 0 \\
 1 - x^2 & \mbox{otherwise}
 \end{cases}


>>> native
[ EIdentifier "f"
, EDelimited "(" ")" [ Right (EIdentifier "x") ]
, ESymbol Rel "="
, EDelimited
    "{"
    ""
    [ Right
        (EArray
           [ AlignLeft , AlignLeft ]
           [ [ [ ENumber "1" ]
             , [ ESymbol Bin "\8722"
               , ENumber "1"
               , ESymbol Rel "\8804"
               , EIdentifier "x"
               , ESymbol Rel "<"
               , ENumber "0"
               ]
             ]
           , [ [ EFraction NormalFrac (ENumber "1") (ENumber "2") ]
             , [ EIdentifier "x" , ESymbol Rel "=" , ENumber "0" ]
             ]
           , [ [ ENumber "1"
               , ESymbol Bin "\8722"
               , ESuper (EIdentifier "x") (ENumber "2")
               ]
             , [ EText TextNormal "otherwise" ]
             ]
           ])
    ]
]