       <a href = "c4lib_prb.sh">c4lib_prb.sh</a>,
          commands to compile and run the sample program.
        </li>
        <li>
          <a href = "c4lib_prb_output.txt">c4lib_prb_output.txt</a>,
          the output file.
        </li>
      </ul>
    </p>

    <h3 align = "center">
      List of Routines:
    </h3>

    <p>
      <ul>
        <li>
          <b>C4_ABS</b> evaluates the absolute value of a C4.
        </li>
        <li>
          <b>C4_ACOS</b> evaluates the inverse cosine of a C4.
