ctionName</span></code>
      is the name of the function, <code class="computeroutput"><span class="identifier">Message</span></code>
      is an error message describing the problem, <code class="computeroutput"><span class="identifier">Val</span></code>
      is the erroneous argument, and <a class="link" href="../policy.html" title="Chapter&#160;18.&#160;Policies: Controlling Precision, Error Handling etc">Policy</a> is the
      current policy in use for the called function.
    </p>
<p>
      The defa