double f(double c_p, double c_n, double t, double s) {
double r7666187 = 1.0;
double r7666188 = s;
double r7666189 = -r7666188;
double r7666190 = exp(r7666189);
double r7666191 = r7666187 + r7666190;
double r7666192 = r7666187 / r7666191;
double r7666193 = c_p;
double r7666194 = pow(r7666192, r7666193);
double r7666195 = r7666187 - r7666192;
double r7666196 = c_n;
double r7666197 = pow(r7666195, r7666196);
double r7666198 = r7666194 * r7666197;
double r7666199 = t;
double r7666200 = -r7666199;
double r7666201 = exp(r7666200);
double r7666202 = r7666187 + r7666201;
double r7666203 = r7666187 / r7666202;
double r7666204 = pow(r7666203, r7666193);
double r7666205 = r7666187 - r7666203;
double r7666206 = pow(r7666205, r7666196);
double r7666207 = r7666204 * r7666206;
double r7666208 = r7666198 / r7666207;
return r7666208;
}