double f(double lambda1, double lambda2, double phi1, double phi2) {
double r3007153 = lambda1;
double r3007154 = lambda2;
double r3007155 = r3007153 - r3007154;
double r3007156 = sin(r3007155);
double r3007157 = phi2;
double r3007158 = cos(r3007157);
double r3007159 = r3007156 * r3007158;
double r3007160 = phi1;
double r3007161 = cos(r3007160);
double r3007162 = sin(r3007157);
double r3007163 = r3007161 * r3007162;
double r3007164 = sin(r3007160);
double r3007165 = r3007164 * r3007158;
double r3007166 = cos(r3007155);
double r3007167 = r3007165 * r3007166;
double r3007168 = r3007163 - r3007167;
double r3007169 = atan2(r3007159, r3007168);
return r3007169;
}