e numbers (this is the same as has been returned
                      from the function <code class="computeroutput"><span class="identifier">force_sign</span><span class="special">()</span></code> described above)
                    </p>
                    <p>
                      The return value defines the outcome of the whole generator.
                      If it is <code class="computeroutput"><span class="keyword">false</span></code>,
                      no further output is generated, immedia