double f(double lambda1, double lambda2, double phi1, double phi2) {
double r3674830 = lambda1;
double r3674831 = lambda2;
double r3674832 = r3674830 - r3674831;
double r3674833 = sin(r3674832);
double r3674834 = phi2;
double r3674835 = cos(r3674834);
double r3674836 = r3674833 * r3674835;
double r3674837 = phi1;
double r3674838 = cos(r3674837);
double r3674839 = sin(r3674834);
double r3674840 = r3674838 * r3674839;
double r3674841 = sin(r3674837);
double r3674842 = r3674841 * r3674835;
double r3674843 = cos(r3674832);
double r3674844 = r3674842 * r3674843;
double r3674845 = r3674840 - r3674844;
double r3674846 = atan2(r3674836, r3674845);
return r3674846;
}