co"># |b = 2, a = 1, 0|</span></span></span>
<span class="r-out co"><span class="r-pr">#&gt;</span> |b = 2, a = 1, 0|</span>
<span class="r-in"><span></span></span>
<span class="r-in"><span><span class="va">d</span> <span class="op">=</span> <span class="fu">deque</span><span class="op">(</span><span class="fl">1</span>, <span class="fl">2</span>, <span class="fl">3</span><span class="op">)</span></span></span>
<span class="r-in"><span><span class="fu"><a href="peek.html">peek</a></span><span class="op">(</