 href="Boolean_Algebra/index.html">Boolean_Algebra</a> : <span class="keyword">functor</span> (<a href="Boolean_Algebra/argument-1-Ok/index.html">Ok</a> : <a href="../../Interface/index.html#module-type-BOOLEAN_ALGEBRA">Interface.BOOLEAN_ALGEBRA</a>) <span>&#45;&gt;</span> <span class="keyword">functor</span> (<a href="Boolean_Algebra/argument-2-Error/index.html">Error</a> : <a href="../../Interface/index.html#module-type-BOOLEAN_ALGEBRA">Interface.BOOLEAN_ALGEBRA</a>) <span>&#45;&gt;</span> <span class="ke