ab&quot; in
v = None</code></pre></div></div><h3 id="boolean"><a href="#boolean" class="anchor"></a>Boolean</h3><div class="odoc-spec"><div class="spec value" id="val-not_" class="anchored"><a href="#val-not_" class="anchor"></a><code><span><span class="keyword">val</span> not_ : <span><span><span class="type-var">'a</span> <a href="#type-t">t</a></span> <span class="arrow">&#45;&gt;</span></span> <span>unit <a href="#type-t">t</a></span></span></code></div><div class="spec-doc"><p><code>not_ p</code> parse