ss="p">,</span> <span class="nx">condition</span><span class="p">,</span> <span class="nx">action</span>
      <span class="nx">prev</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span> <span class="o">=</span> <span class="s1">&#39;FUNC_EXIST&#39;</span> <span class="k">if</span> <span class="nx">prev</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span> <span class="o">is</span> <span class="s1">&#39;?&#39;</span>
      <span class="mi">2</span></pre></