1</span><span class="op">]</span></span></span>
<span class="r-in"><span><span class="fu">zipFastener</span><span class="op">(</span><span class="va">df1</span>, <span class="va">df2</span>, <span class="fl">1</span><span class="op">)</span></span></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   o  o  o  o</span>
<span class="r-out co"><span class="r-pr">#&gt;</span> 11  X  X  X  X</span>
<span class="r-out co"><s