x53EF;&#x80FD;&#x5E74;&#x9F62;&#x306F;21&#x6B73;&#x304B;&#x3089;&#x3067;&#x3059;&#x3002;</p>
</blockquote>
<pre><code class="lang-elm"><span class="hljs-title">canBuyAlcohol</span> : <span class="hljs-type">User</span> -&gt; <span class="hljs-type">Bool</span>
<span class="hljs-title">canBuyAlcohol</span> user =
  <span class="hljs-keyword">case</span> user.age <span class="hljs-keyword">of</span>
    <span class="hljs-type">Nothing</span> -&gt;
      <span class="hljs-type">False</span>

    <span class="h