Hi, I have an object 'VenueGlobal' with a property 'sousVenues' who is a List of SousVenue. I try to test the emptyness of this list in on sentence but i don't know why it doesn't work : I try this : VenueGlobal( sousVenues == null || sousVenues.empty ) but I have this error : org.drools.rule.InvalidRulePackage: [11,53]: unknown:11:53 Unexpected token ')' at org.drools.rule.Package.checkValidity(Package.java:424) I try this : VenueGlobal( sousVenues == null || sousVenues.size == 0 ) but I have this error : Caused by: org.mvel.PropertyAccessException: unable to resolve property: size at org.mvel.optimizers.impl.refl.ReflectiveAccessorOptimizer.getBeanProperty(ReflectiveAccessorOptimizer.java:382) I don't know what the solution ? regards, V. -- View this message in context: http://www.nabble.com/Collection---Emptyness-tp16833060p16833060.html Sent from the drools - user mailing list archive at Nabble.com. _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users