Thanks Steve, Is contains in 3.0.5 - I can't find reference to it in the bundled documentation? Also, do you know whether Object's equals() and Object's hashCode() are used for normal equality conditions:- when h : house() p : person ( residence == ( h ) ) ... Do you also know how the greater than and less than operators are implemented (can we provide a comparator instance)? when r : rank() p : person (rank >= ( r ) ) ... (If this is even possible!?!? - I haven't got this far yet). Thanks in advance. Mike ________________________________ From: rules-users-bounces(a)lists.jboss.org [mailto:rules-users-bounces@lists.jboss.org] On Behalf Of Steven Williams Sent: 23 January 2007 23:00 To: Rules Users List Subject: Re: [rules-users] Rules to detect states in an object graph?!? Hi Michael, To do the opposite approach (where the relationship is navigable from the parent only) you can use the following: when c : Child ( age > 18 ) Parent ( children contains c, type == "SMURF" ) Of course this requires either * the child object in the children collection to be the same as the asserted child object or * the equals/hashcode method to be implemented appropriately in Child cheers Steve On 1/24/07, Anstis, Michael (M.) <manstis1(a)ford.com&gt; wrote: Sorry, me again, I'm putting together some prototype rules that operate on related objects in a graph of objects. I'm adding all objects individually to working memory and then checking the objects are related in the rule to ensure only valid combinations are selected; for example:- //Java code parent.addChild(child) wm.assertObject(parent); wm.assertObject(child); //Rule rule "Adult smurfs" when c : Child ( age > 18, p : parent ) Parent ( parentId == ( p.parentId ) , type == "SMURF" ) then System.out.println("Smurf " + p.getName() + " is " + c.getAge() + " years old." end rule "Adult clangers" when c : Child ( age > 18, p : parent ) Parent ( parentId == ( p.parentId ) , type == "CLANGER" ) then System.out.println("Clanger " + p.getName() + " is " + c.getAge() + " years old." end This requires that the parent-child relationship is navigable from the child end of the relationship -- child.getParent() . What other approaches does anyone else use to implement rules that span related objects? With kind regards, Michael Anstis ------------------------------------------- Next Generation Estimating System * Trafford House (Int) 8 718 2239 * Trafford House (Ext) +44 (0)1268 702239 * < mailto:manstis1@ford.com <mailto:manstis1@ford.com> _______________________________________________ rules-users mailing list rules-users(a)lists.jboss.org https://lists.jboss.org/mailman/listinfo/rules-users -- Steven Williams Supervising Consultant Object Consulting Office: 8615 4500 Mob: 0439 898 668 Fax: 8615 4501 stevenw(a)objectconsulting.com.au www.objectconsulting.com.au consulting | development | training | support our experience makes the difference