odel <code>fit0 = NULL</code> compares <code>fit1</code> to the intercept-only model.</p></dd>


<dt id="arg-dfcom">dfcom<a class="anchor" aria-label="anchor" href="#arg-dfcom"></a></dt>
<dd><p>A single number denoting the
complete-data degrees of freedom of model <code>fit1</code>. If not specified,
it is set equal to <code>df.residual</code> of model <code>fit1</code>. If that cannot
be done, the procedure assumes (perhaps incorrectly) a large sample.</p></dd>


<dt id="arg-df-com">df.com<a class="anchor"