r-in"><span><span class="va">s1</span> <span class="op">&amp;</span> <span class="va">s2</span>     <span class="co"># {1}</span></span></span>
<span class="r-out co"><span class="r-pr">#&gt;</span> {1}</span>
<span class="r-in"><span></span></span>
<span class="r-in"><span><span class="va">s1</span> <span class="op">|</span> <span class="va">s2</span>     <span class="co"># {1, b = 2, b = 4}</span></span></span>
<span class="r-out co"><span class="r-pr">#&gt;</span> {1, b = 2, b = 4}</span>
<span class="r-