code: def useFahlmanActivationFunction(self):
          
          self.activationFunction = self.activationFunctionFahlman
          self.ACTPRIME = self.ACTPRIME_Fahlman
          self.actDeriv = self.actDerivFahlman
          for layer in self:
              layer.minTarget, layer.minActivation = -0.5, -0.5 
              layer.maxTarget, layer.maxActivation = 0.5, 0.5
docs: Change the network to use Fahlman's default activation function for all layers.
          Must be called after all layers have been added.