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<h1>
<span class="number">4.2</span> <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-27.html">Variations on a Scheme—Lazy Evaluation<span class="nowrap">⁠<svg class="external" width="24" height="24" aria-hidden="true"><use xlink:href="#external"/></svg></span></a>
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<ul>
<li>We can experiment with different language design just by modifying the evaluator.</li>
<li>Th