\[\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\left(\sin kx\right)}^{2} + {\left(\sin ky\right)}^{2}\right)}}\right)}\]

\sqrt{\frac{1}{2} \cdot \left(1 + \frac{1}{\sqrt{1 + {\left(\frac{2 \cdot \ell}{Om}\right)}^{2} \cdot \left({\left(\sin kx\right)}^{2} + {\left(\sin ky\right)}^{2}\right)}}\right)}

double f(double l, double Om, double kx, double ky) {
        double r8138 = 1.0;
        double r8139 = 2.0;
        double r8140 = r8138 / r8139;
        double r8141 = l;
        double r8142 = r8139 * r8141;
        double r8143 = Om;
        double r8144 = r8142 / r8143;
        double r8145 = pow(r8144, r8139);
        double r8146 = kx;
        double r8147 = sin(r8146);
        double r8148 = pow(r8147, r8139);
        double r8149 = ky;
        double r8150 = sin(r8149);
        double r8151 = pow(r8150, r8139);
        double r8152 = r8148 + r8151;
        double r8153 = r8145 * r8152;
        double r8154 = r8138 + r8153;
        double r8155 = sqrt(r8154);
        double r8156 = r8138 / r8155;
        double r8157 = r8138 + r8156;
        double r8158 = r8140 * r8157;
        double r8159 = sqrt(r8158);
        return r8159;
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2019179 
(FPCore (l Om kx ky)
  :name "Toniolo and Linder, Equation (3a)"
  (sqrt (* (/ 1.0 2.0) (+ 1.0 (/ 1.0 (sqrt (+ 1.0 (* (pow (/ (* 2.0 l) Om) 2.0) (+ (pow (sin kx) 2.0) (pow (sin ky) 2.0))))))))))

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