[rules-users] How to execute a rule only when a fact is retracted

Hi, How can I ensure that a rule is executed only when a fact is retracted. If I implement the rule using a "not" condition it will execute even when the object was never inserted into the working memory. Is there a way to implement the rule such that it will not execute when a fact is never inserted into the working memory, but executes only when the fact is retracted from the working memory. Thanks, dme -- View this message in context: http://drools.46999.n3.nabble.com/How-to-execute-a-rule-only-when-a-fact-... Sent from the Drools: User forum mailing list archive at Nabble.com.