123 =
  (append (append string_of_int ((+) 1)) (( * ) 2)) 123;;
val satisfies_associative_law : bool = true</code></pre><h4 id="comparisons"><a href="#comparisons" class="anchor"></a>Comparisons</h4><p>The comparison interfaces <a href="Bastet/Interface/module-type-EQ/index.html"><code>Bastet.Interface.EQ</code></a> and <a href="Bastet/Interface/module-type-ORD/index.html"><code>Bastet.Interface.ORD</code></a> are self-explanatory: use the <code>EQ</code> interface to define how to determine whether two val