ref="#t66">66</a></span><span class="t">        <span class="com"># A corner is "exposed" if both adjoining edges are True</span>&nbsp;</span><span class="r"></span></p>
    <p class="mis show_mis"><span class="n"><a id="t67" href="#t67">67</a></span><span class="t">        <span class="nam">c0_exposed</span><span class="op">:</span> <span class="nam">bool</span> <span class="op">=</span> <span class="nam">top</span> <span class="key">and</span> <span class="nam">left</span>  <span class="com"># top-left</s