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History-Register Automata

Grigore, Radu, Tzevelekos, Nikos (2016) History-Register Automata. Logical Methods in Computer Science, 12 (1). pp. 1-32. ISSN 1860-5974.


Programs with dynamic allocation are able to create and use an unbounded number of fresh resources, such as references, objects, files, etc. We propose History-Register Automata (HRA), a new automata-theoretic formalism for modelling such programs. HRAs extend the expressiveness of previous approaches and bring us to the limits of decidability for reachability checks. The distinctive feature of our machines is their use of unbounded memory sets (histories) where input symbols can be selectively stored and compared with symbols to follow. In addition, stored symbols can be consumed or deleted by reset. We show that the combination of consumption and reset capabilities renders the automata powerful enough to imitate counter machines, and yields closure under all regular operations apart from complementation. We moreover examine weaker notions of HRAs which strike different balances between expressiveness and effectiveness.

Item Type: Article
Uncontrolled keywords: register automata, automata over infinite alphabets, infinite systems reachability, freshness, counter automata
Subjects: Q Science > QA Mathematics (inc Computing science) > QA 9 Formal systems, logics
Divisions: Faculties > Sciences > School of Computing > Programming Languages and Systems Group
Depositing User: Radu Grigore
Date Deposited: 17 Mar 2016 19:36 UTC
Last Modified: 29 May 2019 17:06 UTC
Resource URI: (The current URI for this page, for reference purposes)
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