lihood.  If <code>NULL</code> (the default),
    set <code>REML</code> to <code>isREML(object)</code> (see <code><a href="isREML.html">isREML</a></code>).</p></dd>

  <dt id="arg-fixed-only">fixed.only<a class="anchor" aria-label="anchor" href="#arg-fixed-only"></a></dt>
<dd><p>logical indicating if only the fixed effects
    components (terms or formula elements) are sought.  If false, all
    components, including random ones, are returned.</p></dd>

  <dt id="arg-random-only">random.only<a class="anchor"