double f(double c_p, double c_n, double t, double s) {
double r8669785 = 1.0;
double r8669786 = s;
double r8669787 = -r8669786;
double r8669788 = exp(r8669787);
double r8669789 = r8669785 + r8669788;
double r8669790 = r8669785 / r8669789;
double r8669791 = c_p;
double r8669792 = pow(r8669790, r8669791);
double r8669793 = r8669785 - r8669790;
double r8669794 = c_n;
double r8669795 = pow(r8669793, r8669794);
double r8669796 = r8669792 * r8669795;
double r8669797 = t;
double r8669798 = -r8669797;
double r8669799 = exp(r8669798);
double r8669800 = r8669785 + r8669799;
double r8669801 = r8669785 / r8669800;
double r8669802 = pow(r8669801, r8669791);
double r8669803 = r8669785 - r8669801;
double r8669804 = pow(r8669803, r8669794);
double r8669805 = r8669802 * r8669804;
double r8669806 = r8669796 / r8669805;
return r8669806;
}