double f(double x, double y, double z, double t, double a) {
double r1809504 = x;
double r1809505 = y;
double r1809506 = r1809504 + r1809505;
double r1809507 = log(r1809506);
double r1809508 = z;
double r1809509 = log(r1809508);
double r1809510 = r1809507 + r1809509;
double r1809511 = t;
double r1809512 = r1809510 - r1809511;
double r1809513 = a;
double r1809514 = 0.5;
double r1809515 = r1809513 - r1809514;
double r1809516 = log(r1809511);
double r1809517 = r1809515 * r1809516;
double r1809518 = r1809512 + r1809517;
return r1809518;
}