le: italic;">thm</span>(<span
 style="font-style: italic; font-weight: bold;">T</span>)) is
in the concept lattice of theories indexed by <span
 style="font-style: italic; font-weight: bold;">L</span>. The IFF
closure function in the language namespace
</p>
<p style="margin-left: 40px;"><span
 style="font-family: arial; font-style: italic;">clo</span>(<span
 style="font-style: italic; font-weight: bold;">L</span>) : <span
 style="font-family: arial; font-style: italic;">th</span>(<span
 style="font-style: i