;;; Variables and wild cards example
;;;
;;; Peter Cheng.  Jan 2009.
;;;
;;; Instructions
;;; 1 - Load the deffacts and the first rule
;;; 2 - (reset) to load the facts into WM -  look at them in the facts/WM window
;;; 3 - How many activations on the agenda and which fact is/are they associated with?
;;; 4 - Run the model, see what happens.
;;; 5 - (clear) CLIPS
;;; 6 - repeat steps 1-5 for each of the other rules
;;;        Remember you can just select parts of the file and do 'load selection'.
;;; 7 - Add some more facts to the deffacts and write a new rule to put a new fact in WM with the last name.
;;; 8 - Write a new rule that will reverse the order of the first and last names of every one.  



(deffacts some-facts "various facts of the same type"
 (goal default)
	(name peter cheng)
	(name jane smith)
	(name barack obama)
	(name michelle obama))


;;; example 1

(defrule one-particular-pattern-with-literal-symbols-in-LHS
   (goal default)
   (name barack obama)
=>
   (assert (president obama))
)


;;; example  2

(defrule wild-card
   (goal default)
	   (name ? obama)        ; ?ft is the variable for a fact
=>
   (assert (there-is-someone-with-the-name-obama (gensym))))
                  ; (gensym) creates an arbitary symbol, so that each version of this fact will be different
   


;;; example 3

(defrule first-name-when-last-name-is-obama
   (goal default)
   (name ?first obama)                 ; ?first is a variable
=>
   (assert (first-name ?first))        ; put the symbol stored in ?first in this fact
)