ss="keyword">type</span>&nbsp;t&nbsp;=&nbsp;bool&nbsp;=&nbsp;<span class="keyword">false</span>&nbsp;<span class="keywordsign">|</span>&nbsp;<span class="keyword">true</span><br>
&nbsp;&nbsp;<span class="keyword">val</span>&nbsp;not&nbsp;:&nbsp;bool&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;bool<br>
&nbsp;&nbsp;<span class="keyword">external</span>&nbsp;(&nbsp;<span class="keywordsign">&amp;&amp;</span>&nbsp;)&nbsp;:&nbsp;bool&nbsp;<span class="keywordsign">-&gt;</span>&nbsp;bool&nbsp;<span class="ke