he first is a property name and the second is a 
  type specifier as filter, then a route where the designated type satisfies the 
  edge value as type is chosen. Note that this search has no backtrack. 
</div></p>
<a id=Section5.5 name=Section5.5/>
<h3>5.5 &nbsp;Adding Resource Objects and Forward Reference</h3>
<p>In CLOS, a class must be defined before making its instance. A CLOS 
programmer cannot add a slot value to an instance object without the slot 
definition upon the class. In contrast, adding a t