ps://rdrr.io/r/base/unlist.html" class="external-link">unlist</a></span><span class="op">(</span><span class="fu"><a href="https://rdrr.io/r/base/strsplit.html" class="external-link">strsplit</a></span><span class="op">(</span><span class="va">formula</span>, <span class="st">" ~ "</span><span class="op">)</span><span class="op">)</span><span class="op">[</span><span class="fl">2</span><span class="op">]</span></span>
<span>  <span class="va">formula</span> <span class="op">&lt;-</span> <span class="fu"><a 