Recent query processors for complex events filter data streams to match specific patterns and transform streamed data into meaningful information. To specify patterns, complex event processing languages adopt a negation to present an event that should not appear at a specific position. A negation makes queries more expressive forms, but they need to look up indexes each time.
In this paper, we review an efficient processing technique for a negation and propose a technique named CEPIN (Consecutive Events Processing In Negations) for processing consecutive events in a query with negations. The key is to investigate whether a present event type is identical to the previous one. If so, a calculation to find out a result sequence range is not necessary and conclusively the required time for a negation and a reverse order of links processing can be saved. Our experiment shows a reduction in numbers of processes and calculations per event.