an><span class="p">.</span><span class="nb">maxval</span><span class="p">(</span><span class="n">iarr</span><span class="p">),</span><span class="s1">&#39;like maxval()&#39;</span><span class="p">)</span><span class="w"></span>
<span class="w">   </span><span class="c">! but more generally it can return the Nth lowest value.</span>
<span class="w">   </span><span class="k">call </span><span class="n">unit_check</span><span class="p">(</span><span class="s1">&#39;valnth&#39;</span><span class="p">,</span><sp