Monad/index.html#type-t">Monad.t</a></span>)</span> <span>&#45;&gt;</span> <span class="type-var">'c</span> <span>&#45;&gt;</span> <span><span class="type-var">'b</span> <a href="../Monad/index.html#type-t">Monad.t</a></span></code></dt><dt class="spec value" id="val-(&lt;&lt;=)"><a href="#val-(&lt;&lt;=)" class="anchor"></a><code><span class="keyword">val</span> (&lt;&lt;=) : <span>(<span><span class="type-var">'a</span> <a href="../Extend/index.html#type-t">Extend.t</a></span> <span>&#45;&gt;</span> <span