[Lisa-users] basic question

[Kaveh K. <ka...@ha...>]

Greetings,

Please forgive this very basic question.

Do the "facts" of the system have to be CLOS classes or templates?   
Is it possible to have LISA do inference over facts expressed as  
thunks or arbitrary lisp expressions?

For example, I have a movie scene, and I am developing a system for  
automatically placing the camera to best shoot the scene.  I would  
like to be able to express rules such as the following:

(defrule rule-1 (:cf 0.8)
   (is-first-shot-of *scene*)
   =>
   (make-establishing-shot *scene*))

Also, how would one best express things such as the following as a rule?

   (let ((actor-1 (current-subject *scene*))
	(actor-2 (non-current-subject *scene*)))
     (if (> (viewer-identification-with actor-1)
	   (viewer-identification-with actor-2))
	(make-closeup-shot actor-1)
	(make-over-the-shoulder-shot actor-1)))

I obviously am just starting investigating rule-based systems, so  
pointers to articles or texts with a practical bent would be  
appreciated.

Regards,

Kaveh