double f(double lambda1, double lambda2, double phi1, double phi2) {
double r3632876 = lambda1;
double r3632877 = lambda2;
double r3632878 = r3632876 - r3632877;
double r3632879 = sin(r3632878);
double r3632880 = phi2;
double r3632881 = cos(r3632880);
double r3632882 = r3632879 * r3632881;
double r3632883 = phi1;
double r3632884 = cos(r3632883);
double r3632885 = sin(r3632880);
double r3632886 = r3632884 * r3632885;
double r3632887 = sin(r3632883);
double r3632888 = r3632887 * r3632881;
double r3632889 = cos(r3632878);
double r3632890 = r3632888 * r3632889;
double r3632891 = r3632886 - r3632890;
double r3632892 = atan2(r3632882, r3632891);
return r3632892;
}