<<< native
[ EDelimited
    "["
    ")"
    [ Right
        (EGrouped [ EIdentifier "a" , ESymbol Bin "+" , EIdentifier "b" ])
    ]
, EDelimited
    "{"
    "}"
    [ Right (EFraction NormalFrac (EIdentifier "a") (EIdentifier "b"))
    , Left "|"
    , Right (EFraction NormalFrac (EIdentifier "d") (EIdentifier "e"))
    , Right (ESymbol Pun ";")
    , Right (EIdentifier "a")
    , Right (ESymbol Bin "+")
    , Right (EIdentifier "b")
    , Right (ESymbol Bin "+")
    , Right (EIdentifier "a")
    , Right (ESymbol Bin "+")
    , Right (EIdentifier "b")
    ]
]
>>> tex
\left\lbrack {a + b} \right)\left\{ \frac{a}{b} \middle| \frac{d}{e};a + b + a + b \right\}