Hi, We are thinking of using Drools rules engine, for our application. But we have few questions, that we would really happy to get explanations about. 1) Is the latest version Drools 5.1 supports backward chaining? If so since which release you started to support backward chaining? 2) Are you using "Crisp Logic"? (we can only insert "facts" that are true/false) 3) Whether Drools allow to intermingle the RuleBase and the WorkingMemory? Hope to hear from you! Thanks. -- Best Regards, Nirmal C.S.Nirmal J. Fernando Department of Computer Science & Engineering, Faculty of Engineering, University of Moratuwa, Sri Lanka. Blog: http://nirmalfdo.blogspot.com/