double f(double lambda1, double lambda2, double phi1, double phi2) {
double r3046242 = lambda1;
double r3046243 = lambda2;
double r3046244 = r3046242 - r3046243;
double r3046245 = sin(r3046244);
double r3046246 = phi2;
double r3046247 = cos(r3046246);
double r3046248 = r3046245 * r3046247;
double r3046249 = phi1;
double r3046250 = cos(r3046249);
double r3046251 = sin(r3046246);
double r3046252 = r3046250 * r3046251;
double r3046253 = sin(r3046249);
double r3046254 = r3046253 * r3046247;
double r3046255 = cos(r3046244);
double r3046256 = r3046254 * r3046255;
double r3046257 = r3046252 - r3046256;
double r3046258 = atan2(r3046248, r3046257);
return r3046258;
}