\[\frac{2 + \left(\left(\sqrt{2} \cdot \left(\sin x - \frac{\sin y}{16}\right)\right) \cdot \left(\sin y - \frac{\sin x}{16}\right)\right) \cdot \left(\cos x - \cos y\right)}{3 \cdot \left(\left(1 + \frac{\sqrt{5} - 1}{2} \cdot \cos x\right) + \frac{3 - \sqrt{5}}{2} \cdot \cos y\right)}\]

\frac{2 + \left(\left(\sqrt{2} \cdot \left(\sin x - \frac{\sin y}{16}\right)\right) \cdot \left(\sin y - \frac{\sin x}{16}\right)\right) \cdot \left(\cos x - \cos y\right)}{3 \cdot \left(\left(1 + \frac{\sqrt{5} - 1}{2} \cdot \cos x\right) + \frac{3 - \sqrt{5}}{2} \cdot \cos y\right)}

double f(double x, double y) {
        double r8219 = 2.0;
        double r8220 = sqrt(r8219);
        double r8221 = x;
        double r8222 = sin(r8221);
        double r8223 = y;
        double r8224 = sin(r8223);
        double r8225 = 16.0;
        double r8226 = r8224 / r8225;
        double r8227 = r8222 - r8226;
        double r8228 = r8220 * r8227;
        double r8229 = r8222 / r8225;
        double r8230 = r8224 - r8229;
        double r8231 = r8228 * r8230;
        double r8232 = cos(r8221);
        double r8233 = cos(r8223);
        double r8234 = r8232 - r8233;
        double r8235 = r8231 * r8234;
        double r8236 = r8219 + r8235;
        double r8237 = 3.0;
        double r8238 = 1.0;
        double r8239 = 5.0;
        double r8240 = sqrt(r8239);
        double r8241 = r8240 - r8238;
        double r8242 = r8241 / r8219;
        double r8243 = r8242 * r8232;
        double r8244 = r8238 + r8243;
        double r8245 = r8237 - r8240;
        double r8246 = r8245 / r8219;
        double r8247 = r8246 * r8233;
        double r8248 = r8244 + r8247;
        double r8249 = r8237 * r8248;
        double r8250 = r8236 / r8249;
        return r8250;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019179 +o rules:numerics
(FPCore (x y)
  :name "Diagrams.TwoD.Path.Metafont.Internal:hobbyF from diagrams-contrib-1.3.0.5"
  (/ (+ 2.0 (* (* (* (sqrt 2.0) (- (sin x) (/ (sin y) 16.0))) (- (sin y) (/ (sin x) 16.0))) (- (cos x) (cos y)))) (* 3.0 (+ (+ 1.0 (* (/ (- (sqrt 5.0) 1.0) 2.0) (cos x))) (* (/ (- 3.0 (sqrt 5.0)) 2.0) (cos y))))))

Backtrace

result arity mismatch; expected number of values not received expected: 2 received: 1 in: local-binding form values...: 0		L	C
loop	/data/pavpan/nightlies/herbie/various-cleanup/src/core/extraction.rkt	25	2
(unnamed)	/data/pavpan/nightlies/herbie/various-cleanup/src/core/simplify.rkt	26	0
simplify!	/data/pavpan/nightlies/herbie/various-cleanup/src/mainloop.rkt	217	0
run-improve43	/data/pavpan/nightlies/herbie/various-cleanup/src/mainloop.rkt	339	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