Hi again, The rules below produce the same effect. I can't decide which one to use. So, can someone please points out the pros and cons of each rule? What is the rule of thumb when resolving such situations? Thanks in appreciation. (defrule _1.5 (not(e5crt ?val&:(= ?val 0)|:(= ?val 1)|:(= ?val 8))) => (assert (result .))) (defrule _1.5a (e5crt ?val&~0&~1&~8) => (assert (result .))) (defrule _1.5b (e5crt ?val&:(<> ?val 0)&:(<> ?val 1)&:(<> ?val 8)) => (assert (result .))) -- Regards, Jerry --------------------------------------------------------------------- To unsubscribe, send the words 'unsubscribe jess-users [EMAIL PROTECTED]' in the BODY of a message to [EMAIL PROTECTED], NOT to the list (use your own address!) List problems? Notify [EMAIL PROTECTED] ---------------------------------------------------------------------
