<<< native
[ ESub (EIdentifier "\981") (EIdentifier "n")
, EDelimited "(" ")" [ Right (EIdentifier "\954") ]
, ESymbol Rel "="
, EFraction
    NormalFrac
    (ENumber "1")
    (EGrouped
       [ ENumber "4"
       , ESuper (EIdentifier "\960") (ENumber "2")
       , ESuper (EIdentifier "\954") (ENumber "2")
       ])
, ESubsup (ESymbol Op "\8747") (ENumber "0") (ESymbol Ord "\8734")
, EFraction
    NormalFrac
    (EGrouped
       [ EMathOperator "sin"
       , EDelimited
           "(" ")" [ Right (EIdentifier "\954") , Right (EIdentifier "R") ]
       ])
    (EGrouped [ EIdentifier "\954" , EIdentifier "R" ])
, EFraction
    NormalFrac
    (ESymbol Ord "\8706")
    (EGrouped [ ESymbol Ord "\8706" , EIdentifier "R" ])
, EDelimited
    "["
    "]"
    [ Right (ESuper (EIdentifier "R") (ENumber "2"))
    , Right
        (EFraction
           NormalFrac
           (EGrouped
              [ ESymbol Ord "\8706"
              , ESub (EIdentifier "D") (EIdentifier "n")
              , EDelimited "(" ")" [ Right (EIdentifier "R") ]
              ])
           (EGrouped [ ESymbol Ord "\8706" , EIdentifier "R" ]))
    ]
, ESpace (1 % 6)
, EIdentifier "d"
, EIdentifier "R"
]
>>> typst
phi.alt_n lr((kappa)) eq frac(1, 4 pi^2 kappa^2) integral_0^oo frac(sin lr((kappa R)), kappa R) frac(diff, diff R) lr([R^2 frac(diff D_n lr((R)), diff R)]) thin d R