span>
<span class="r-out co"><span class="r-pr">#&gt;</span>    V1 V2 V3 V4</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 1   X  X  X  X</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 4   o  o  o  o</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 2   X  X  X  X</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 5   o  o  o  o</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 3   X  X  X  X</span>
<span class="r-out co"><span class="r-pr">#&