Adding Invariants to Event Zone Automata

Abstract

Abstract. Recently, a new approach to the symbolic model checking of timed automata based on a partial order semantics was introduced, which relies on event zones that use vectors of event occurrences instead of clock zones that use vectors of clock values grouped in polyhedral clock constraints. Symbolic state exploration with event zones rather than clock zones can result in significant reductions in the number of symbolic states explored. In this work, we show how to extend the event zone approach to networks of automata with local state invariants, an important feature for modeling complex timed systems. To avoid formalizing local states, we attach to each transition an urgency constraint, that allows to code local state invariants. We have integrated the extension into a prototype tool with event zones and reported very promising experimental results.

A New Approach of Partial Order Reduction Technique for Parallel Timed Automata Model Checking

“…Partial order path, which concerns only the order of dependent transitions, is used to avoid splitting symbolic states into pieces. In [8] and [9], the authors decouple enumeration orders and execution orders using extended states, of which the clock values can be negative. Roughly speaking, given two independent transitions and , enumerating the sequence results in one symbolic state, which is the combination of two symbolic states w.r.t.…”

A concurrency-preserving translation from time Petri nets to networks of timed automata

“…These orders induced by causality and by time stamping of events appear in [1], where timed MSCs (Message Sequence Charts) and MSCs with timing constraints are considered, and in [2] where the authors consider distributed timed automata with independently evolving clocks. In [24,26], an independence relation is defined among the actions of a timed automaton using a diamond property that takes time into account. This relation is used to define partial order reduction techniques that avoid the combinatorial explosion in the analysis of timed automata.…”

A Concurrency-Preserving Translation from Time Petri Nets to Networks of Timed Automata

“…These orders induced by causality and by the time stamping of events appear in [1], where timed MSCs (Message Sequence Charts) and MSCs with timing constraints are considered and in [2] where the authors consider distributed timed automata with independently evolving clocks. In [16], [18], an independence relation is defined among the actions of a timed automaton using a diamond property that takes time into account. This relation is used to define partial order reduction techniques that avoid the combinatorial explosion in the analysis of timed automata.…”