[rules-users] Detecting an expired Event

Hello everyone, I'm working on a Drools system that uses stream mode to handle incoming events from clients and I am trying to adapt some existing code to Drools. I'm unsure if it's fully applicable but I'm hoping someone can shed light on to it. My current execution path is... 1. Client generates an event 2. Server receives event and places it into a timer for a specified time. 3. When the timer is up the server notifies the client. but I don't see any way that lets you know when event B finishes on its own. Is this even possible? Thanks. Cheers, Jean-Philippe