y component; or</em></span>
      </p>
<p>
        <span class="emphasis"><em>"the corresponding mathematical function is not mathematically
        defined.</em></span>
      </p>
</blockquote></div>
<div class="blockquote"><blockquote class="blockquote"><p>
        <span class="emphasis"><em>"Note 2: A mathematical function is mathematically defined
        for a given set of argument values if it is explicitly defined for that set
        of argument values or if its limiting value exists and does not de