#define sigmoid(x) (1/(1+exp(-x)))

#define sigmoid_deriv(x) (1/((1+exp(-x))*(1+exp(x))))

#define soft_not(x) (1-(x))

#define soft_and(x, y) ((x)*(y))

#define soft_or(x,y) (1-(1-(x))*(1-(y)))

#define soft_greater(x,y,delta) (sigmoid(((x)-(y))/(delta)))

#define soft_less(x,y,delta) (sigmoid(((y)-(x))/(delta)))

float soft_equal(float x, float y, float delta){
  float z = (x-y)/delta;
  return exp(-z*z);
}

float soft_if(float p, float x, float y){
  return p*x + (1-p)*y;
}

Vector soft_if_vector(float p, Vector x, Vector y){
  Vector v = p*x + (1-p)*y;
  return v;
}