<<< tex
   \int_0^1 x^x\,\mathrm{d}x = \sum_{n = 1}^\infty{(-1)^{n + 1}\,n^{-n}}

>>> native
[ ESubsup (ESymbol Op "\8747") (ENumber "0") (ENumber "1")
, ESuper (EIdentifier "x") (EIdentifier "x")
, ESpace (1 % 6)
, EStyled TextNormal [ EIdentifier "d" ]
, EIdentifier "x"
, ESymbol Rel "="
, EUnderover
    True
    (ESymbol Op "\8721")
    (EGrouped [ EIdentifier "n" , ESymbol Rel "=" , ENumber "1" ])
    (ESymbol Ord "\8734")
, EGrouped
    [ ESuper
        (EDelimited
           "(" ")" [ Right (ESymbol Op "\8722") , Right (ENumber "1") ])
        (EGrouped [ EIdentifier "n" , ESymbol Bin "+" , ENumber "1" ])
    , ESpace (1 % 6)
    , ESuper
        (EIdentifier "n")
        (EGrouped [ ESymbol Op "\8722" , EIdentifier "n" ])
    ]
]