 
Summary: EventClock Automata:
A Determinizable Class of Timed Automata \Lambda
Rajeev Alur y Limor Fix z Thomas A. Henzinger x
Abstract. We introduce eventrecording automata. An eventrecording automaton
is a timed automaton that contains, for every event a, a clock that records the time
of the last occurrence of a. The class of eventrecording automata is, on one hand,
expressive enough to model (finite) timed transition systems and, on the other hand,
determinizable and closed under all boolean operations. As a result, the language
inclusion problem is decidable for eventrecording automata. We present a translation
from timed transition systems to eventrecording automata, which leads to an algorithm
for checking if two timed transition systems have the same set of timed behaviors.
We also consider eventpredicting automata, which contain clocks that predict the
time of the next occurrence of an event. The class of eventclock automata, which contain
both eventrecording and eventpredicting clocks, is a suitable specification language for
realtime properties. We provide an algorithm for checking if a timed automaton meets
a specification that is given as an eventclock automaton.
1 Introduction
Finite automata are instrumental for the modeling and analysis of many phenomena within com
puter science. In particular, automata theory plays an important role in the verification of con
current finitestate systems [15, 21]. In the trace model for concurrent computation, a system is
