er">4</span><span class="special">,</span><span class="number">8</span><span class="special">);</span>
    <span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="string">"-- adding   "</span> <span class="special">&lt;&lt;</span> <span class="identifier">inter_val</span> <span class="special">&lt;&lt;</span> <span class="string">" -----------------------------------------"</span> <span class="special">&lt;&lt;</span> <span class="identifier">endl</span><span class="special">