Lately, I have occasionally tried to raise an alert for something I consider a bug, but there was no comment. Here's another one. rule "Faults coincide" when f1 : MyEvent( key == "faultType1", value == "ALARM" ) over window:length( 1 ) f2 : MyEvent( key == "faultType2", value == "ALARM" ) over window:length( 1 ) then System.out.println( "************ both faults are active! f1.key = " + f1.getKey() + " f2.key = " + f2.getKey() ); end This rule fires after the insertion of a single fact matching the event bound to f1. Detailed code can be found on the user's list. -W