 8) rather than the <code class="mendoza-code">x</code> defined to be 10. The problem is the
reuse of the symbol <code class="mendoza-code">x</code> inside the macro, which overshadowed the original
binding. This problem is called the
<a href="https://en.wikipedia.org/wiki/Hygienic_macro#The_hygiene_problem">hygiene
problem</a> and is solved in many programming languages
(such as Scheme) by hygienic macros. Hygienic macros prevent such
accidental captures, but usually constrain the kinds of macros that can 