double f(double lambda1, double lambda2, double phi1, double phi2) {
double r26484342 = lambda1;
double r26484343 = lambda2;
double r26484344 = r26484342 - r26484343;
double r26484345 = sin(r26484344);
double r26484346 = phi2;
double r26484347 = cos(r26484346);
double r26484348 = r26484345 * r26484347;
double r26484349 = phi1;
double r26484350 = cos(r26484349);
double r26484351 = sin(r26484346);
double r26484352 = r26484350 * r26484351;
double r26484353 = sin(r26484349);
double r26484354 = r26484353 * r26484347;
double r26484355 = cos(r26484344);
double r26484356 = r26484354 * r26484355;
double r26484357 = r26484352 - r26484356;
double r26484358 = atan2(r26484348, r26484357);
return r26484358;
}