</span></span>
<span class="r-in"><span><span class="co"># We create a main user-level function</span></span></span>
<span class="r-in"><span><span class="co"># The computation is done by an internal function</span></span></span>
<span class="r-in"><span><span class="co"># Here we compare stop_up with a regular stop</span></span></span>
<span class="r-in"><span></span></span>
<span class="r-in"><span><span class="va">main_function</span> <span class="op">=</span> <span class="kw">function</span><span class=