PAC</a>,
      a FORTRAN77 library which
      includes a version of the <b>XERROR</b> library.
    </p>

    <h3 align = "center">
      Reference:
    </h3>

    <p>
      <ol>
        <li>
          Phyllis Fox, Andrew Hall, Norman Schryer,<br>
          Algorithm 528:<br>
          Framework for a Portable Library,<br>
          ACM Transactions on Mathematical Software,<br>
          Volume 4, Number 2, June 1978, page 176-188.
        </li>
        <li>
          Ron Jones, David Kahaner,<br>
        