 class 
of classes is called <i>metaclass</i> in CLOS. So, rdfs:Class and rdfs:Datatype 
in RDFS vocabulary are metaclasses in CLOS.</p>
<p align="center"><img alt="RDFS Graph" 
src="FIGURES/RDFSHierarchy.PNG" border="0"/> </p>
<p align="center"><b>Figure 5.1 RDFS Hierarchy Graph</b></p>
<p></p>
<p>The notion of metaclass, class, and instance is very important in CLOS. 
Therefore, predicates for these categories on RDF resources are prepared. See 
the followings.</p>
<code>gx-user(33): (rsc-object-p 
rdfs:C