Figure 3

Processing of events: simplified algorithm (handling of delayed events omitted). At each iteration, the trigger conditions of active events e_a∈E_A that are not persistent are checked. If the trigger condition of such an event has changed from true (1) to false (0), the event is removed from E_A. The next step comprises the evaluation of the triggers of all events. If its trigger changes from false to true, an event is added to the set of active events E_A. An event with its trigger changed from true to false is removed from the list of inactive events. After the processing of all triggers, the event e of highest priority in the set of active events is chosen for execution by the function choose(E_A). Note that priorities are not always defined, or multiple events may have an identical priority. The function choose(E_A) is therefore more complex than shown in this figure. The selected event is then processed, i.e., all of its assignments are evaluated, and afterwards the triggers of all events in E have to be evaluated again, because of possible mutual influences between the events. The algorithm proceeds until the set E_A of active events is empty.