We solve some decision problems for timed automata which were raised by S. Tripakis in [Tri04] and by E. Asarin in [Asa04]. In particular, we show that one cannot decide whether a given timed automaton is determinizable or whether the complement of a timed regular language is timed regular. We show that the problem of the minimization of the number of clocks of a timed automaton is undecidable....

Timed automata constitute a well adapted model for real-time aspects. However, a classical forward analysis algorithm used to verify safety properties has been showed to be incorrect in the general framework of timed automata. Nevertheless, it is correct when we restrict the class to timed automata with only non-diagonal guards. The aim of this work is to understand the role of diagonal guards ...

Abstract Temporal graphs represent graph evolution over time, and have been receiving considerable research attention. Work on expressing temporal patterns or discovering motifs typically assumes relatively simple constraints, such as journeys or, more generally, existential possibly with finite delays. In this paper we propose to use timed automata express leading a general powerful notion of ...

Timed pushdown automata (tpda) are an expressive formalism combining recursion with a rich logic of timing constraints. We prove that reachability relations tpda expressible in linear arithmetic, generalising Presburger arithmetic and rational arithmetic. The main technical ingredients novel quantifier elimination result for clock constraints (used to simplify the syntax transitions), use diffe...

Event logs are often one of the main sources information to understand behavior a system. While numerous approaches have extracted partial from event logs, in this work, we aim at inferring global model system its logs. We consider real-time systems, which can be modeled with Timed Automata: our approach is thus Automata learner. There handful related however, they might require lot parameters ...

Automata with weights (multiplicities) in (max,+) algebra form a class of timed automata. Determinism is a crucial property for numerous results on (max,+) automata and, in particular, for applications to performance evaluation and control of a large class of timed discrete event systems. In this paper, we show how to build a deterministic (max,+) automaton equivalent to a live and safe timed P...