\[R \cdot \left(2 \cdot \tan^{-1}_* \frac{\sqrt{{\left(\sin \left(\frac{\phi_1 - \phi_2}{2}\right)\right)}^{2} + \left(\left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \sin \left(\frac{\lambda_1 - \lambda_2}{2}\right)\right) \cdot \sin \left(\frac{\lambda_1 - \lambda_2}{2}\right)}}{\sqrt{1 - \left({\left(\sin \left(\frac{\phi_1 - \phi_2}{2}\right)\right)}^{2} + \left(\left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \sin \left(\frac{\lambda_1 - \lambda_2}{2}\right)\right) \cdot \sin \left(\frac{\lambda_1 - \lambda_2}{2}\right)\right)}}\right)\]

R \cdot \left(2 \cdot \tan^{-1}_* \frac{\sqrt{{\left(\sin \left(\frac{\phi_1 - \phi_2}{2}\right)\right)}^{2} + \left(\left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \sin \left(\frac{\lambda_1 - \lambda_2}{2}\right)\right) \cdot \sin \left(\frac{\lambda_1 - \lambda_2}{2}\right)}}{\sqrt{1 - \left({\left(\sin \left(\frac{\phi_1 - \phi_2}{2}\right)\right)}^{2} + \left(\left(\cos \phi_1 \cdot \cos \phi_2\right) \cdot \sin \left(\frac{\lambda_1 - \lambda_2}{2}\right)\right) \cdot \sin \left(\frac{\lambda_1 - \lambda_2}{2}\right)\right)}}\right)

double f(double R, double lambda1, double lambda2, double phi1, double phi2) {
        double r3978 = R;
        double r3979 = 2.0;
        double r3980 = phi1;
        double r3981 = phi2;
        double r3982 = r3980 - r3981;
        double r3983 = r3982 / r3979;
        double r3984 = sin(r3983);
        double r3985 = pow(r3984, r3979);
        double r3986 = cos(r3980);
        double r3987 = cos(r3981);
        double r3988 = r3986 * r3987;
        double r3989 = lambda1;
        double r3990 = lambda2;
        double r3991 = r3989 - r3990;
        double r3992 = r3991 / r3979;
        double r3993 = sin(r3992);
        double r3994 = r3988 * r3993;
        double r3995 = r3994 * r3993;
        double r3996 = r3985 + r3995;
        double r3997 = sqrt(r3996);
        double r3998 = 1.0;
        double r3999 = r3998 - r3996;
        double r4000 = sqrt(r3999);
        double r4001 = atan2(r3997, r4000);
        double r4002 = r3979 * r4001;
        double r4003 = r3978 * r4002;
        return r4003;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2020045 
(FPCore (R lambda1 lambda2 phi1 phi2)
  :name "Distance on a great circle"
  :precision binary64
  (* R (* 2 (atan2 (sqrt (+ (pow (sin (/ (- phi1 phi2) 2)) 2) (* (* (* (cos phi1) (cos phi2)) (sin (/ (- lambda1 lambda2) 2))) (sin (/ (- lambda1 lambda2) 2))))) (sqrt (- 1 (+ (pow (sin (/ (- phi1 phi2) 2)) 2) (* (* (* (cos phi1) (cos phi2)) (sin (/ (- lambda1 lambda2) 2))) (sin (/ (- lambda1 lambda2) 2))))))))))

Backtrace

hash-ref: no value found for key key: '(/ #<enode 1(91)> #<enode 732(732)>)		L	C
for-loop	/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding/regraph/egraph.rkt	270	6
update-leader!	/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding/regraph/egraph.rkt	265	0
for-loop	/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding/regraph/main.rkt	77	2
prune-phase	/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding/regraph/main.rkt	74	0
for-loop	/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/core/simplify.rkt	80	4
for-loop	/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/core/simplify.rkt	76	2
(unnamed)	/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/core/simplify.rkt	56	0
(unnamed)	/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/core/simplify.rkt	38	0
simplify!	/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/mainloop.rkt	224	0
run-improve47	/data/pavpan/nightlies/herbie/simplify-regraph-rebuilding-2/src/mainloop.rkt	346	0
.../more-scheme.rkt:261:28	unknown
run	/opt/racket-7.5/share/pkgs/profile-lib/main.rkt	39	2
profile-thunk16	/opt/racket-7.5/share/pkgs/profile-lib/main.rkt	9	0
(unnamed)	/opt/racket-7.5/collects/racket/private/more-scheme.rkt	261	28

Falling back on racket egraph because egg-herbie package not installed (more)

Reproduce

Backtrace