em> space).</li>
<li>Consider adding all the primes in an interval. Using <code>filter</code> and <code>reduce</code>, we waste a lot of space storing lists.</li>
<li>Streams are lazy lists. They are the clever idea of using sequence manipulations without incurring the cost.</li>
<li>We only construct an item of the stream when it is needed.</li>
<li>We have <code>cons-stream</code>, <code>stream-car</code>, <code>stream-cdr</code>, <code>the-empty-stream</code>, and <code>stream-null?</code>.</li>
<li>The 