 the binomial coefficient C(N,K) as an R8.
        </li>
        <li>
          <b>R8_EPSILON</b> returns the R8 roundoff unit.
        </li>
        <li>
          <b>R8_FACTORIAL</b> computes the factorial of N.
        </li>
        <li>
          <b>R8_FACTORIAL_LOG</b> computes log(factorial(N)).
        </li>
        <li>
          <b>R8_FACTORIAL_LOG_VALUES</b> returns values of log(factorial(n)).
        </li>
        <li>
          <b>R8_FACTORIAL_VALUES</b> returns values of the real factorial fun