#45;&gt;</span> <span><span class="type-var">'a</span> list</span> <span>&#45;&gt;</span> <span><span class="type-var">'a</span> list</span></code></dt><dt class="spec value" id="val-hd"><a href="#val-hd" class="anchor"></a><code><span class="keyword">val</span> hd : <span><span class="type-var">'a</span> list</span> <span>&#45;&gt;</span> <span class="type-var">'a</span></code></dt><dt class="spec value" id="val-tl"><a href="#val-tl" class="anchor"></a><code><span class="keyword">val</span> tl : <span><spa