double f(double lambda1, double lambda2, double phi1, double phi2) {
double r1214458 = lambda1;
double r1214459 = lambda2;
double r1214460 = r1214458 - r1214459;
double r1214461 = sin(r1214460);
double r1214462 = phi2;
double r1214463 = cos(r1214462);
double r1214464 = r1214461 * r1214463;
double r1214465 = phi1;
double r1214466 = cos(r1214465);
double r1214467 = sin(r1214462);
double r1214468 = r1214466 * r1214467;
double r1214469 = sin(r1214465);
double r1214470 = r1214469 * r1214463;
double r1214471 = cos(r1214460);
double r1214472 = r1214470 * r1214471;
double r1214473 = r1214468 - r1214472;
double r1214474 = atan2(r1214464, r1214473);
return r1214474;
}