s="section"><a name="PROPERTIES-OF-FLUID-OBJECTS"></a> Properties of fluid objects </h4>

<p>Fluid objects are quite like <a href="http://www.lispworks.com/documentation/HyperSpec/Body/26_glo_s.htm#standard_object">standard objects</a> in most respects.  However, any fluid object has <code class="api-name">fluid-class</code> as its metaclass, and missing slots in such fluid instances are not distinguished from unbound slots.  Namely, if <var>F</var> is a fluid instance of class <var>K</var>, and <var>R</var