double f(double lambda1, double lambda2, double phi1, double phi2) {
double r14051652 = lambda1;
double r14051653 = lambda2;
double r14051654 = r14051652 - r14051653;
double r14051655 = sin(r14051654);
double r14051656 = phi2;
double r14051657 = cos(r14051656);
double r14051658 = r14051655 * r14051657;
double r14051659 = phi1;
double r14051660 = cos(r14051659);
double r14051661 = sin(r14051656);
double r14051662 = r14051660 * r14051661;
double r14051663 = sin(r14051659);
double r14051664 = r14051663 * r14051657;
double r14051665 = cos(r14051654);
double r14051666 = r14051664 * r14051665;
double r14051667 = r14051662 - r14051666;
double r14051668 = atan2(r14051658, r14051667);
return r14051668;
}