="spec value" id="val-singleton"><a href="#val-singleton" class="anchor"></a><code><span class="keyword">val</span> singleton : <a href="index.html#type-key">key</a> <span>&#45;&gt;</span> <a href="index.html#type-value">value</a> <span>&#45;&gt;</span> <a href="index.html#type-t">t</a></code></dt><dt class="spec value" id="val-remove"><a href="#val-remove" class="anchor"></a><code><span class="keyword">val</span> remove : <a href="index.html#type-key">key</a> <span>&#45;&gt;</span> <a href="index.html#type