5.1 The KnowledgeWorks Listener

Figure 5.2 KnowledgeWorks Listener

The KnowledgeWorks Listener is obtained by choosing Window > KnowledgeWorks > Listener . This tool is based on the LispWorks Common Prolog Logic Listener (see Common Prolog for further details). Input is taken as being a goal expression to be satisfied unless no predicate of that name and arity (number of arguments) exists in which case it is taken as a Lisp expression. That is, the input may be either


as defined in Forward chaining, or


with the former interpretation taking priority when ambiguous. Interaction is Prolog-style, so when the bindings which satisfy a goal are printed, pressing Return terminates execution, and entering ; (semi-colon) and Return (or just clicking on the Next button at the bottom) looks for the next solution to the goal.

The File , Leashing and Spy menus behave as for the Common Prolog Logic Listener (see Common Prolog) and the Values , Debug and History menus behave as for the Lisp Listener (see the Common LispWorks User Guide ).

KnowledgeWorks and Prolog User Guide (Macintosh version) - 29 Feb 2008