class="st">"After"</span><span class="op">)</span>,</span>
<span>  diff.inv <span class="op">=</span> <span class="cn">FALSE</span></span>
<span><span class="op">)</span></span></code></pre></div>
    </div>

    <div class="section level2">
    <h2 id="arguments">Arguments<a class="anchor" aria-label="anchor" href="#arguments"></a></h2>


<dl><dt id="arg-fml">fml<a class="anchor" aria-label="anchor" href="#arg-fml"></a></dt>
<dd><p>Either a formula of the type <code>var1 + ... + varN ~ treat</code> or
<cod