n>&#45;&gt;</span> <span><span>(<a href="argument-1-B/index.html#type-t">B.t</a> * <a href="argument-1-B/index.html#type-t">B.t</a>)</span> option</span></code></dt><dt class="spec value" id="val-log"><a href="#val-log" class="anchor"></a><code><span class="keyword">val</span> log : <span>(<a href="argument-1-B/index.html#type-t">B.t</a> * <a href="argument-1-B/index.html#type-t">B.t</a>)</span> <span>&#45;&gt;</span> <span><a href="index.html#type-t">t</a> option</span></code></dt><dt class="spec value" id