 apply : <span><span>(<span class="type-var">'a</span> <span>&#45;&gt;</span> <span class="type-var">'b</span>)</span> <a href="index.html#type-t">t</a></span> <span>&#45;&gt;</span> <span><span class="type-var">'a</span> <a href="index.html#type-t">t</a></span> <span>&#45;&gt;</span> <span><span class="type-var">'b</span> <a href="index.html#type-t">t</a></span></code></dt></dl></details></div></div></div><dl><dt class="spec value" id="val-pure"><a href="#val-pure" class="anchor"></a><code><span class="key