[rules-users] Truth maintenance and RHS variables

Hi there, I'm working on a rule that will alert me when there is no events from the sensors for a while. So, first idea was to use time window and matches in condition side, to match all types of sensors, and then to print that something is wrong. rule "Alert if there is no activity" when not StateEvent(itemName matches "door.*|presence.*|luminosity.*") over window:time( 1m ) from entry-point "EventStream" then System.out.println("Alert: one sensor is not working"); end First change was to add a timer, as truth maintenance will fire this rule the first time, but not forever. So i add a timer to fire the rule every 20 seconds, for example. rule "Alert if there is no activity" timer (cron:0/20 * * * * ?) when not StateEvent(itemName matches "door.*|presence.*|luminosity.*") over window:time( 1m ) from entry-point "EventStream" then System.out.println("Alert: one sensor is not working"); end The second thing i want to achieve is to print what specific sensor is not working, but i understand that as there is no StateEvent, i can't declare a variable, for example. rule "Alert if there is no activity" timer (cron:0/20 * * * * ?) when not $event: StateEvent(itemName matches "door.*|presence.*|luminosity.*") over window:time( 1m ) from entry-point "EventStream" then System.out.println("Alert: one sensor is not working: " + $event.getItemName()); So, do you know how can i know which sensor is not working? must i rewrite the rule to achieve this? is this possible? Thanks for your help. end