Hello, I have 2 simple rules: rule one when A() not(B()) then System.out.println("a"); end rule two when A() then System.out.println("b"); end A and B are plain java objects with no properties. When I create stateful knowledge session (default configuration) and do the following: session1.insert(new A()); session1.fireAllRules(); MarshallerFactory.newMarshaller(knowledgeBase).marshall(new ByteArrayOutputStream(), session1); I get an infite loop (resulting byte array eats up all heap space, no matter how much I set). Am I doing sth wrong or is it a bug? br, maciek prochniak