;)</code> with <code>true</code> as the empty element <code>((&amp;&amp;), true)</code>:</p><pre><code class="ml"># let empty = true;;
val empty : bool = true

# let satisfies_identity_law = (false &amp;&amp; empty) = false;;
val satisfies_identity_law : bool = true

# let satisfies_associative_law = (true &amp;&amp; (true &amp;&amp; false)) = ((true &amp;&amp; true) &amp;&amp; false);;
val satisfies_associative_law : bool = true</code></pre></li><li><p>The <a href="Bastet/Bool/Disjunctive/Monoid/index.html