double f(double lambda1, double lambda2, double phi1, double phi2) {
double r3653062 = lambda1;
double r3653063 = lambda2;
double r3653064 = r3653062 - r3653063;
double r3653065 = sin(r3653064);
double r3653066 = phi2;
double r3653067 = cos(r3653066);
double r3653068 = r3653065 * r3653067;
double r3653069 = phi1;
double r3653070 = cos(r3653069);
double r3653071 = sin(r3653066);
double r3653072 = r3653070 * r3653071;
double r3653073 = sin(r3653069);
double r3653074 = r3653073 * r3653067;
double r3653075 = cos(r3653064);
double r3653076 = r3653074 * r3653075;
double r3653077 = r3653072 - r3653076;
double r3653078 = atan2(r3653068, r3653077);
return r3653078;
}