Number equality test fails in CLIPS pattern matching?

Question

I have this following rule in my CLIPS file:

(defrule check-final (declare (salience 12))
    ?scnt <- (set-count (value ?v) (class ?c))
    (test (= ?v ?*tot         


        

Answer 1

The most likely explanation is that at some point the equality test is being satisfied and then the value of the global is changed before the rule executes.

CLIPS> (deftemplate set-count (slot value) (slot class))
CLIPS> 
(defglobal ?*total* = 0)
CLIPS> 
(defrule check-final (declare (salience 12))
    ?scnt <- (set-count (value ?v) (class ?c))
    (test (= ?v ?*total*))
    =>
    (printout T ?*total* " == " ?v crlf)
)
CLIPS> (bind ?*total* 9)
9
CLIPS> (assert (set-count (value 9) (class a)))

CLIPS> (bind ?*total* 14)
14
CLIPS> (run)
14 == 9
CLIPS> (bind ?*total* 2)
2
CLIPS> (assert (set-count (value 2) (class b)))

CLIPS> (bind ?*total* 5)
5
CLIPS> (run)
5 == 2
CLIPS>