ight="24" aria-hidden="true"><use xlink:href="#external"/></svg></span></a>
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<h3 id="ex4.54" class="anchor">
<a class="anchor__link link" href="#ex4.54" aria-hidden="true">#</a> <a class="link" href="https://mitp-content-server.mit.edu/books/content/sectbyfn/books_pres_0/6515/sicp.zip/full-text/book/book-Z-H-28.html#%25_thm_4.54">Exercise 4.54<span class="nowrap">⁠<svg class="external" width="24" height="24" aria-hidden="true"><use xlink:href="#external"/></svg></span></a>
</h3>
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