GEBRA_F/argument-2-Error/index.html">Error</a> : <a href="../../Interface/index.html#module-type-HEYTING_ALGEBRA">Interface.HEYTING_ALGEBRA</a>) <span>&#45;&gt;</span> <a href="../../Interface/index.html#module-type-HEYTING_ALGEBRA">Interface.HEYTING_ALGEBRA</a> <span class="keyword">with</span> <span class="keyword">type</span> <a href="module-type-HEYTING_ALGEBRA_F/index.html#type-t">t</a> = <span><span>(<a href="module-type-HEYTING_ALGEBRA_F/argument-1-Ok/index.html#type-t">Ok.t</a>, <a href="module-typ