">concat</span><span class="op">(</span><span class="va">bv1</span>, <span class="va">bv3</span><span class="op">)</span></span></span>
<span class="r-in"><span><span class="fu"><a href="dim-methods.html">dim</a></span><span class="op">(</span><span class="va">bv4</span><span class="op">)</span><span class="op">[</span><span class="fl">4</span><span class="op">]</span> <span class="op">==</span> <span class="fl">3</span></span></span>
<span class="r-out co"><span class="r-pr">#&gt;</span> [1] TRUE</span>
<s