code: @Override
      public double membership(double x) {
          if (Double.isNaN(x)) {
              return Double.NaN;
          }
          return height * Math.exp(-Math.abs(10.0 / width * (x - center)));
      }
docs: Computes the membership function evaluated at `x`
  
  @param x
  @return `h \times \exp(-|10 / w (x - c)|)`
  
  where `h` is the height of the Term,
  `w` is the width of the Spike,
  `c` is the center of the Spike