code: @Override
      public double hedge(double x) {
          return Op.isLE(x, 0.5)
                  ? 2.0 * x * x
                  : 1.0 - 2.0 * (1.0 - x) * (1.0 - x);
      }
docs: Computes the hedge for the membership function value `x`
  
  @param x is a membership function value
  @return ` \begin{cases} 2x^2 & \mbox{if $x \le 0.5$} \cr 1-2(1-x)^2 &
  \mbox{otherwise} \cr \end{cases}`