Exception for Migdal et al, Equation (51)

Math

\[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}\]

C

double f(double k, double n) {
        double r55419 = 1.0;
        double r55420 = k;
        double r55421 = sqrt(r55420);
        double r55422 = r55419 / r55421;
        double r55423 = 2.0;
        double r55424 = atan2(1.0, 0.0);
        double r55425 = r55423 * r55424;
        double r55426 = n;
        double r55427 = r55425 * r55426;
        double r55428 = r55419 - r55420;
        double r55429 = r55428 / r55423;
        double r55430 = pow(r55427, r55429);
        double r55431 = r55422 * r55430;
        return r55431;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019194 
(FPCore (k n)
  :name "Migdal et al, Equation (51)"
  (* (/ 1.0 (sqrt k)) (pow (* (* 2.0 PI) n) (/ (- 1.0 k) 2.0))))

Backtrace

get-representation: Unknown representation #f		L	C
(unnamed)	/data/pavpan/nightlies/herbie/master/src/core/localize.rkt	23	13
hash-ref!	/opt/racket-7.0/collects/racket/private/more-scheme.rkt	376	2
map	/opt/racket-7.0/collects/racket/private/map.rkt	35	13
parse-loop30	/opt/racket-7.0/collects/racket/match/compiler.rkt	418	15
hash-ref!	/opt/racket-7.0/collects/racket/private/more-scheme.rkt	376	2
map	/opt/racket-7.0/collects/racket/private/map.rkt	35	13
parse-loop30	/opt/racket-7.0/collects/racket/match/compiler.rkt	418	15
hash-ref!	/opt/racket-7.0/collects/racket/private/more-scheme.rkt	376	2
map	/opt/racket-7.0/collects/racket/private/map.rkt	35	13
parse-loop30	/opt/racket-7.0/collects/racket/match/compiler.rkt	418	15
hash-ref!	/opt/racket-7.0/collects/racket/private/more-scheme.rkt	376	2
localize-error	/data/pavpan/nightlies/herbie/master/src/core/localize.rkt	61	0
localize!	/data/pavpan/nightlies/herbie/master/src/mainloop.rkt	123	0
run-iter!	/data/pavpan/nightlies/herbie/master/src/mainloop.rkt	323	0
for-loop	/data/pavpan/nightlies/herbie/master/src/mainloop.rkt	359	4
run-improve47	/data/pavpan/nightlies/herbie/master/src/mainloop.rkt	342	0
(unnamed)	/opt/racket-7.0/collects/racket/private/more-scheme.rkt	261	28
run	/opt/racket-7.0/share/pkgs/profile-lib/main.rkt	39	2
profile-thunk16	/opt/racket-7.0/share/pkgs/profile-lib/main.rkt	9	0
(unnamed)	/opt/racket-7.0/collects/racket/private/more-scheme.rkt	261	28