-weight: bold;">      3</span>   <span style="font-weight: bold;">      3</span>  </span>
<span class="r-out co"><span class="r-pr">#&gt;</span>                                      4         4  </span>
<span class="r-out co"><span class="r-pr">#&gt;</span>                                      5         5  </span>
<span class="r-out co"><span class="r-pr">#&gt;</span> </span>
<span class="r-out co"><span class="r-pr">#&gt;</span> Column names: b, c</span>
<span class="r-in"><span><span class="fu"><a href="b