on is not a fresh literal type.</p>
<ol start="2">
<li>Literal widening happens whenever a fresh literal type reaches a
<em>mutable</em> location.</li>
</ol>
<p>One example of a mutable location is a <code>let</code> variable declaration. In
contrast, a <code>const</code> variable declaration is not a mutable location.
Compare the following two statements:</p>
<p><pre class="typescript-code"><span class="tm-kw">const</span> <span class="tm-vr">one</span> = <span class="tm-num">1</span>; <span class="tm-cmt"