iv><div class="odoc-spec"><div class="spec type anchored" id="type-t"><a href="#type-t" class="anchor"></a><code><span><span class="keyword">type</span> t</span><span> = <span><a href="../../../IStdlib/GOption/index.html#type-some">IStdlib.GOption.some</a> <a href="#type-t0">t0</a></span></span></code></div><div class="spec-doc"><p>Memory type with an environment for on-demand symbol evaluation</p></div></div><div class="odoc-spec"><div class="spec value anchored" id="val-unset_oenv"><a href="#val-unset_oen