__exp__D
double __exp__D(double, double);
r = __exp__D(s, y)/x;
return(__exp__D(u.a, u.b));
y = __exp__D(y, z);
return (__exp__D(s.a, s.b));
return(__exp__D(u.a, u.b));
y = __exp__D(y, z);
double __exp__D(double, double);