ral logarithm system.
        </li>
        <li>
          <b>ERF_VALUES</b> returns some values of the ERF or "error" function for testing.
        </li>
        <li>
          <b>ERROR_F</b> evaluates the error function ERF(X).
        </li>
        <li>
          <b>ERROR_F_INVERSE</b> inverts the error function ERF.
        </li>
        <li>
          <b>EULER_CONSTANT</b> returns the value of the Euler-Mascheroni constant.
        </li>
        <li>
          <b>EULER_NUMBER</b> computes the Euler num