variables, only on lexical <i>references</i> to them in the source,
analyzed transitively. For instance, if a variable <code>x</code>'s
initialization expression refers to a function whose body refers to
variable <code>y</code> then <code>x</code> depends on <code>y</code>.
Specifically:
</p>

<ul>
<li>
A reference to a variable or function is an identifier denoting that