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

\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 r22442 = atan2(1.0, 0.0);
        double r22443 = 2.0;
        double r22444 = r22442 / r22443;
        double r22445 = 1.0;
        double r22446 = b;
        double r22447 = r22446 * r22446;
        double r22448 = a;
        double r22449 = r22448 * r22448;
        double r22450 = r22447 - r22449;
        double r22451 = r22445 / r22450;
        double r22452 = r22444 * r22451;
        double r22453 = r22445 / r22448;
        double r22454 = r22445 / r22446;
        double r22455 = r22453 - r22454;
        double r22456 = r22452 * r22455;
        return r22456;
}

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/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
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