[rules-users] Anti-rules and infinate loops

Hello, I have a set of rules that determine a target date for a business object based on which rule criteria the object matches. When the business object is asserted, the target date field may or may not be null. My problem is if the business object does not match any of the rules I would like the target date set to null and since there are multiple rule possibly affecting the same object I would rather not create an "anti-rule" for each rule which sets the target date to null. I've tried creating a rule with a higher salience value which sets the target date to null, if it is not already, and modifies the object but when the object matches another rule and modifies the object again it goes into an infinite loop. I could probably set the target date to null before asserting it into the rule engine but I was hoping to keep it self contained. Here's an example of what I'm talking about: rule "Pre" salience 10 no-loop true when $bo : MyObject( targetDate != null ) then Date tmp = null; $bo.setTargetDate(tmp); modify($bo); end rule "Post a" no-loop true when $bo : MyObject( targetDate == null, criteriaMatches == "A") $someDate : ThisDateObject(); then $bo.setTargetDate($someDate); modify($bo); end rule "Post b" no-loop true when $bo : MyObject( targetDate == null, criteriaMatches == "B" ) $someDate : ThatDateObject(); then $bo.setTargetDate($someDate); modify($bo); end etc... I'm pretty sure there is a simple answer but it just won't come to me. Thanks for any help. Myles -- eBusiness Solutions Engineer CGI ISMC - DynaDocs DynaDocs Global Solutions 160 Elgin St., 17th Floor Ottawa,ON K2C 2P4 Office: (613) 781-4338 Fax: (613) 781-3821 CONFIDENTIALITY NOTICE: Proprietary/Confidential Information belonging to CGI Group Inc. and its affiliates may be contained in this message. If you are not a recipient indicated or intended in this message (or responsible for delivery of this message to such person), or you think for any reason that this message may have been addressed to you in error, you may not use or copy or deliver this message to anyone else. In such case, you should destroy this message and are asked to notify the sender by reply email.