Undecidability of Bisimilarity by Defender's Forcing

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14330%2F08%3A00026472" target="_blank" >RIV/00216224:14330/08:00026472 - isvavai.cz</a>

Alternative codes found

RIV/61989100:27240/08:00018940

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Undecidability of Bisimilarity by Defender's Forcing

Original language description

tirling (1996, 1998) proved the decidability of bisimilarity on so-called normed pushdown processes. This result was substantially extended by Senizergues(1998, 2005) who showed the decidability of bisimilarity for regular (or equational) graphs of finite out-degree; this essentially coincides with weak bisimilarity of processes generated by (unnormed) pushdown automata where the epsilon-transitions can only deterministically pop the stack. The question of decidability of bisimilarity for the more general class of so called Type -1 systems, which is equivalent to weak bisimilarity on unrestricted epsilon-popping pushdown processes, was left open. This was repeatedly indicated by both Stirling and Senizergues. Here we answer the question negatively, that is, we show the undecidability of bisimilarity on Type -1 systems, even in the normed case. We achieve the result by applying a technique we call Defender's Forcing, referring to the bisimulation games. The idea is simple, yet powerful.

Czech name

Nerozhodnutelnost bisimulace pomoci tlaku obránce

Czech description

tirling (1996, 1998) proved the decidability of bisimilarity on so-called normed pushdown processes. This result was substantially extended by Senizergues(1998, 2005) who showed the decidability of bisimilarity for regular (or equational) graphs of finite out-degree; this essentially coincides with weak bisimilarity of processes generated by (unnormed) pushdown automata where the epsilon-transitions can only deterministically pop the stack. The question of decidability of bisimilarity for the more general class of so called Type -1 systems, which is equivalent to weak bisimilarity on unrestricted epsilon-popping pushdown processes, was left open. This was repeatedly indicated by both Stirling and Senizergues. Here we answer the question negatively, that is, we show the undecidability of bisimilarity on Type -1 systems, even in the normed case. We achieve the result by applying a technique we call Defender's Forcing, referring to the bisimulation games. The idea is simple, yet powerful.

Type

J_x - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)

CEP classification

IN - Informatics

OECD FORD branch

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Project

<a href="/en/project/1M0567" target="_blank" >1M0567: Centre for Applied Cybernetics</a><br>

Continuities

Z - Vyzkumny zamer (s odkazem do CEZ)

Publication year

2008

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of the ACM

ISSN

0004-5411

e-ISSN

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Volume of the periodical

55/2008

Issue of the periodical within the volume

1

Country of publishing house

US - UNITED STATES

Number of pages

26

Pages from-to

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UT code for WoS article

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EID of the result in the Scopus database

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