cl:typep x rdfs:Resource), but more efficient a little bit. 
</div></p>
<p><a id="SWCLOSclass-p" name="SWCLOSclass-p"/>
<div class="titlebar">
<div class="defname">rdf-class-p <i>thing</i></div>
<div class="deftype">[Function]]</div></div>
<div class="defdescribe">returns <a 
  href="http://www.franz.com/support/documentation/8.0/ansicl/glossary/t.htm#true">true</a>, 
  if <i>thing</i> is a class of resource in RDF. Actually, this function returns 
  true, if <i>thing</i> is rdfs:Class or an instance of rdf