Re: [rules-users] can drools support complex rules

Your question is funny. First you ask if Drools is capable of managing complex rules and then you mention examples of extremely simple rules? :) Drools is FOL complete and so can represent any well formed First Order Logic expression. Anyway, I will use this message to advertise some of the temporal reasoning features that we have on Drools 5 for the benefit of anyone interested. There are several ways of authoring such rules, depending on how you model your problem domain. One possible way of doing them is: #1: rule "If a customer login within 5 minutes from two different locations, mark the user invalid." when $l1 : CustomerLogin( ) $l2 : CustomerLogin( userId == l1.$id, location != $l1.id, timestamp after[0s, 5m] $l1.timestamp ) then // mark user as invalid end In the previous example I assumed both login objects would be in working memory, but you can easily query for the previous login in an external datasource, pulling the data from the previous login on-demand for the reasoning cycle. #2: rule "If the customer location is not on a list of valid locations, mark the user invalid" when $l : CustomerLogin( location not memberOf $validLocations ) then // mark the user invalid end In the above rule, I assume the valid locations list is a global list, but you can as easily model locations as being facts on your working memory or a service end point that you can call to validate the location. #3: rule “Customer login from more than 5 locations in the last one month” when $customer : Customer( $id : id ) $locations : Set( size > 5 ) from accumulate( CustomerLogin( customerId == $id, $loc : location ) over window:time( 30d ), collectSet( $loc ) ) then // do something as the customer logged in from more than 5 locations in the last 30 days end In the previous rule I decided to use sliding windows, just to show how that feature can be used to simplify rules, but again, there are several ways of doing it. I strongly recommend you read Drools manual. http://www.jboss.org/drools/documentation.html Cheers, Edson 2009/5/19 Bhushan Bhangale <bhushan_bhangale(a)kaleconsultants.com&gt; -- Edson Tirelli JBoss Drools Core Development JBoss, a division of Red Hat @ www.jboss.com