&gt;</span></span> <span class="type-var">'b</span></span></code></div></div><div class="odoc-spec"><div class="spec value anchored" id="val-of_underlying_node"><a href="#val-of_underlying_node" class="anchor"></a><code><span><span class="keyword">val</span> of_underlying_node : <span><span class="type-var">'a</span> <span class="arrow">&#45;&gt;</span></span> <span class="type-var">'b</span></span></code></div></div><div class="odoc-spec"><div class="spec value anchored" id="val-kind"><a href="#val-kind" c