\[\frac{4}{\left(\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}}\]

\frac{4}{\left(\left(3 \cdot \pi\right) \cdot \left(1 - v \cdot v\right)\right) \cdot \sqrt{2 - 6 \cdot \left(v \cdot v\right)}}

double f(double v) {
        double r210021 = 4.0;
        double r210022 = 3.0;
        double r210023 = atan2(1.0, 0.0);
        double r210024 = r210022 * r210023;
        double r210025 = 1.0;
        double r210026 = v;
        double r210027 = r210026 * r210026;
        double r210028 = r210025 - r210027;
        double r210029 = r210024 * r210028;
        double r210030 = 2.0;
        double r210031 = 6.0;
        double r210032 = r210031 * r210027;
        double r210033 = r210030 - r210032;
        double r210034 = sqrt(r210033);
        double r210035 = r210029 * r210034;
        double r210036 = r210021 / r210035;
        return r210036;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019194 
(FPCore (v)
  :name "Falkner and Boettcher, Equation (22+)"
  (/ 4.0 (* (* (* 3.0 PI) (- 1.0 (* v v))) (sqrt (- 2.0 (* 6.0 (* v v)))))))

Backtrace

get-representation: Unknown representation #f		L	C
(unnamed)	/data/pavpan/nightlies/herbie/js-tweaks/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
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/js-tweaks/src/core/localize.rkt	61	0
localize!	/data/pavpan/nightlies/herbie/js-tweaks/src/mainloop.rkt	123	0
run-iter!	/data/pavpan/nightlies/herbie/js-tweaks/src/mainloop.rkt	323	0
for-loop	/data/pavpan/nightlies/herbie/js-tweaks/src/mainloop.rkt	359	4
run-improve47	/data/pavpan/nightlies/herbie/js-tweaks/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