I think Richard Patten wrote: > Hello everybody, > How do I check if a particular fact exists in the knowledge base and if it does >I want to retract it if I dont know the fact-id in advance. I tried using the exists >command in a rule but it works only once, that is if there is a fact in the knowledge >base then when I the rule will fire for the first time, but if I retract the fact, >reassert it and ask to run again then the rule wont fire. > thanks > Richard. >
Easy -- just don't use "exists." Just write the rule to match the fact. You could also consider using a defquery, if you want to find the fact at a specific time -- i.e., on the RHS of a rule, or from Java. --------------------------------------------------------- Ernest Friedman-Hill Distributed Systems Research Phone: (925) 294-2154 Sandia National Labs FAX: (925) 294-2234 Org. 8920, MS 9012 [EMAIL PROTECTED] PO Box 969 http://herzberg.ca.sandia.gov Livermore, CA 94550 -------------------------------------------------------------------- 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] --------------------------------------------------------------------
