Wrap in in ()'s like this: $tc : TaskContext( times contains (getTimeByID(ETimeID.NOW)) ) I have not personally tried this exact scenario, but the concept is the same as other scenarios I use this for. The ()'s identifies that evaluation should be used here, except that it's not really an eval() because the contents don't returne true/false, but rather it's just java code to be processed, and the output can then be used in the evaluation. I do this with matches like this: LookupFact ( $lookupValue : value ) $sf : SomeFact ( value matches ("(?i)" + $lookupValue) ) From: rules-users-bounces(a)lists.jboss.org [mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Hezi Stern Sent: Wednesday, November 23, 2011 7:51 AM To: rules-users(a)lists.jboss.org Subject: [rules-users] How to use contains with a function Hi all, I encountered the following issue: As an example TaskConectxt() holds a list of time related objects called times. I would like to write a rule which ideally would filter the TaskContext according to a specific time object. The problematic restriction is that this time object is derived using a helper function (imported), in this case called getTimeByID which received as input an enum ID of a time and returns the desired time object. Ideally the rule would like something like this: rule "verify time" when $tc: TaskContext(times contains getTimeByID(ETimeID.NOW)) then //something end unfortunately this does not work. Is there any way to call a function with a param? Is there a better alternative method than this one? Thanks, Hezi