<br>The below code is an example from the HTDP (no yelling ). Could someone explain the highlighted part in detail?  I want something that is detailed enough because I understand the general idea. <br><br><pre class="scheme">
<font size="4"><span class="comment">;; <code class="scheme"><span class="variable">last-occurrence</span> <span class="selfeval">:</span> <span class="variable">symbol</span> <span class="variable">list-of-star</span>  <tt>-&gt;</tt>  <span class="variable">star</span> <span class="keyword">or</span> <span class="builtin">false</span></code></span><br>
<span class="comment">;; to find the last star record in <code class="scheme"><span class="variable">alostars</span></code> that contains <code class="scheme"><span class="variable">s</span></code> in <code class="scheme"><span class="variable">name</span></code> field</span><br>
(<span class="keyword">define</span> (<span class="variable">last-occurrence</span> <span class="variable">s</span> <span class="variable">alostars</span>)<br>  (<span class="keyword">cond</span><br>    [(<span class="builtin">empty?</span> <span class="variable">alostars</span>) <span class="builtin">false</span>]<br>
    [<span class="keyword">else</span> (<span class="keyword">local</span> ((<span class="keyword">define</span> <span class="variable">r</span> (<span class="variable">last-occurrence</span> <span class="variable">s</span> (<span class="builtin">rest</span> <span class="variable">alostars</span>))))<br>
            (<span class="keyword">cond</span><br>              [<span style="background-color: rgb(255, 0, 0);">(</span><span style="background-color: rgb(255, 0, 0);" class="builtin">star?</span><span style="background-color: rgb(255, 0, 0);"> </span><span style="background-color: rgb(255, 0, 0);" class="variable">r</span><span style="background-color: rgb(255, 0, 0);">)</span> <span class="variable">r</span>]<br>
              [(<span class="builtin">symbol=?</span> (<span class="builtin">star-name</span> (<span class="builtin">first</span> <span class="variable">alostars</span>)) <span class="variable">s</span>) (<span class="builtin">first</span> <span class="variable">alostars</span>)]<br>
              [<span class="keyword">else</span> false]))]))<br><br>Thanks in advance.<br><br>Regards,<br>Emeka<br></font></pre><br>