Expression for tanh in tanh.c is incorrect

[MBHelectronics]

double tanh(double x)
{
  double x0 = exp(x);
  double x1 = 1.0 / x0;

  return ((x0 + x1) / (x0 - x1));
}

Should be: return ((x0 - x1) / (x0 + x1)); see e.g.
https://en.wikipedia.org/wiki/Hyperbolic_function#Definitions

[emard]

Thanks for spotting it, I fixed it in source now.
I think also binary library has to be rebuilt for this change to take effect.