Hostname: page-component-74656f9884-npj9w Total loading time: 0 Render date: 2026-11-10T11:43:31.814Z Has data issue: false hasContentIssue false

Relating timed and register automata†

Published online by Cambridge University Press:  05 December 2014

DIEGO FIGUEIRA*
Affiliation:
University of Edinburgh, 10 Crichton Street, Edinburgh EH8 9AB, United Kingdom INRIA, ENS Cachan, LSV, 61 avenue du Président Wilson 94235 Cachan, France Institute of Informatics, University of Warsaw, Banacha 2, 02-097 Warszawa, Poland Email: dfigueir@inf.ed.ac.uk, ph209519@mimuw.edu.pl, sl@mimuw.edu.pl
PIOTR HOFMAN
Affiliation:
Institute of Informatics, University of Warsaw, Banacha 2, 02-097 Warszawa, Poland Email: dfigueir@inf.ed.ac.uk, ph209519@mimuw.edu.pl, sl@mimuw.edu.pl
SŁAWOMIR LASOTA
Affiliation:
Institute of Informatics, University of Warsaw, Banacha 2, 02-097 Warszawa, Poland Email: dfigueir@inf.ed.ac.uk, ph209519@mimuw.edu.pl, sl@mimuw.edu.pl
*
‡ Corresponding author.
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the 'Save PDF' action button.

Timed and register automata are well-known models of computation over timed and data words, respectively. The former has clocks that allow to test the lapse of time between two events, whilst the latter includes registers that can store data values for later comparison. Although these two models behave differently in appearance, several decision problems have the same (un)decidability and complexity results for both models. As a prominent example, emptiness is decidable for alternating automata with one clock or register, both with non-primitive recursive complexity. This is not by chance.

This work confirms that there is indeed a tight relationship between the two models. We show that a run of a timed automaton can be simulated by a register automaton over ordered data domain, and conversely that a run of a register automaton can be simulated by a timed automaton. These are exponential time reductions hold both in the finite and infinite words settings. Our results allow to transfer decidability results back and forth between these two kinds of models, as well complexity results modulo an exponential time reduction. We justify the usefulness of these reductions by obtaining new results on register automata.

Information

Type
Paper
Copyright
Copyright © Cambridge University Press 2014