double f(double lambda1, double lambda2, double phi1, double phi2) {
double r2552663 = lambda1;
double r2552664 = lambda2;
double r2552665 = r2552663 - r2552664;
double r2552666 = sin(r2552665);
double r2552667 = phi2;
double r2552668 = cos(r2552667);
double r2552669 = r2552666 * r2552668;
double r2552670 = phi1;
double r2552671 = cos(r2552670);
double r2552672 = sin(r2552667);
double r2552673 = r2552671 * r2552672;
double r2552674 = sin(r2552670);
double r2552675 = r2552674 * r2552668;
double r2552676 = cos(r2552665);
double r2552677 = r2552675 * r2552676;
double r2552678 = r2552673 - r2552677;
double r2552679 = atan2(r2552669, r2552678);
return r2552679;
}