Use the --timeout flag to change the timeout.
R \cdot \sqrt{\left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) \cdot \left(\left(\lambda_1 - \lambda_2\right) \cdot \cos \left(\frac{\phi_1 + \phi_2}{2}\right)\right) + \left(\phi_1 - \phi_2\right) \cdot \left(\phi_1 - \phi_2\right)}double f(double R, double lambda1, double lambda2, double phi1, double phi2) {
double r152833868 = R;
double r152833869 = lambda1;
double r152833870 = lambda2;
double r152833871 = r152833869 - r152833870;
double r152833872 = phi1;
double r152833873 = phi2;
double r152833874 = r152833872 + r152833873;
double r152833875 = 2.0;
double r152833876 = r152833874 / r152833875;
double r152833877 = cos(r152833876);
double r152833878 = r152833871 * r152833877;
double r152833879 = r152833878 * r152833878;
double r152833880 = r152833872 - r152833873;
double r152833881 = r152833880 * r152833880;
double r152833882 = r152833879 + r152833881;
double r152833883 = sqrt(r152833882);
double r152833884 = r152833868 * r152833883;
return r152833884;
}
herbie shell --seed 2019124
(FPCore (R lambda1 lambda2 phi1 phi2)
:name "Equirectangular approximation to distance on a great circle"
(* R (sqrt (+ (* (* (- lambda1 lambda2) (cos (/ (+ phi1 phi2) 2))) (* (- lambda1 lambda2) (cos (/ (+ phi1 phi2) 2)))) (* (- phi1 phi2) (- phi1 phi2))))))