principal square root of a C4.
        </li>
        <li>
          <b>C4_TANH</b> evaluates the complex hyperbolic tangent.
        </li>
        <li>
          <b>C4_UNIFORM_01</b> returns a unit pseudorandom C4.
        </li>
        <li>
          <b>C8_ARGUMENT</b> returns the argument of a C8.
        </li>
        <li>
          <b>C8_ATAN</b> evaluates the inverse tangent of a C8.
        </li>
        <li>
          <b>C8_LOG</b> evaluates the logarithm of a C8.
        </li>
        <li>
         