 <span>&#45;&gt;</span> <span class="keyword">functor</span> (<a href="Involutive_Heyting_Algebra/argument-2-Error/index.html">Error</a> : <a href="../../Interface/index.html#module-type-INVOLUTIVE_HEYTING_ALGEBRA">Interface.INVOLUTIVE_HEYTING_ALGEBRA</a>) <span>&#45;&gt;</span> <span class="keyword">sig</span> ... <span class="keyword">end</span></code></div><div class="spec module" id="module-Boolean_Algebra"><a href="#module-Boolean_Algebra" class="anchor"></a><code><span class="keyword">module</span> <a