<div class="sourceCode" id="cb9"><pre class="sourceCode r"><code class="sourceCode r"><a class="sourceLine" id="cb9-1" data-line-number="1">x &lt;-<span class="st"> </span><span class="kw">c</span>(<span class="st">"a"</span>, <span class="st">"b"</span>, <span class="st">"c"</span>)</a>
<a class="sourceLine" id="cb9-2" data-line-number="2">y &lt;-<span class="st"> </span><span class="kw">c</span>(<span class="st">"a"</span>, <span class="st">"b"</span>, <span class="st">"b"</span>, <span class="st">"c"</sp