Hello, you can use not like this Rule a When not( (aaa == “bbb”) && (bbb == “aaa”) ) Then // do smth End -- View this message in context: http://drools.46999.n3.nabble.com/not-operation-available-in-drools-tp4017936p4017938.html Sent from the Drools: User forum mailing list archive at Nabble.com.