\[\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right)\]

\left(\frac{\pi}{2} \cdot \frac{1}{b \cdot b - a \cdot a}\right) \cdot \left(\frac{1}{a} - \frac{1}{b}\right)

double f(double a, double b) {
        double r17305 = atan2(1.0, 0.0);
        double r17306 = 2.0;
        double r17307 = r17305 / r17306;
        double r17308 = 1.0;
        double r17309 = b;
        double r17310 = r17309 * r17309;
        double r17311 = a;
        double r17312 = r17311 * r17311;
        double r17313 = r17310 - r17312;
        double r17314 = r17308 / r17313;
        double r17315 = r17307 * r17314;
        double r17316 = r17308 / r17311;
        double r17317 = r17308 / r17309;
        double r17318 = r17316 - r17317;
        double r17319 = r17315 * r17318;
        return r17319;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019195 
(FPCore (a b)
  :name "NMSE Section 6.1 mentioned, B"
  (* (* (/ PI 2.0) (/ 1.0 (- (* b b) (* a a)))) (- (/ 1.0 a) (/ 1.0 b))))

Backtrace

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