double f(double lambda1, double lambda2, double phi1, double phi2) {
double r10059699 = lambda1;
double r10059700 = lambda2;
double r10059701 = r10059699 - r10059700;
double r10059702 = sin(r10059701);
double r10059703 = phi2;
double r10059704 = cos(r10059703);
double r10059705 = r10059702 * r10059704;
double r10059706 = phi1;
double r10059707 = cos(r10059706);
double r10059708 = sin(r10059703);
double r10059709 = r10059707 * r10059708;
double r10059710 = sin(r10059706);
double r10059711 = r10059710 * r10059704;
double r10059712 = cos(r10059701);
double r10059713 = r10059711 * r10059712;
double r10059714 = r10059709 - r10059713;
double r10059715 = atan2(r10059705, r10059714);
return r10059715;
}