0, X=1, U>0, and U=1,
respectively. As opposed to CTL, qualitative PCTL does not have
a small model property, and there are even qualitative PCTL
formulae which have only infinite-state models. Nevertheless,
we show that the satisfiability problem for qualitative PCTL is
EXPTIME-complete and we give an exponential-time algorithm
which for a given formula computes a finite description of a
model (if it exists), or answers "not satisfiable" (otherwise).
We also consider the finite satisfiability problem and provide
analogous results. That is, we show that the finite
satisfiability problem for qualitative PCTL is
EXPTIME-complete, and every finite satisfiable formula has a
model of an exponential size which can effectively be
constructed in exponential time. Finally, we give some results
about the quantitative PCTL, where the numerical bounds in
probability constraints can be arbitrary rationals between 0
and 1. We prove that the problem whether a given quantitative
PCTL formula has a model of the branching degree at most k,
where k > 1 is an arbitrary but fixed constant, is highly
undecidable. We also show that every satisfiable formula F has
a model with branching degree at most |F| + 2. However, this
does not yet imply the undecidability of the satisfiability
problem for quantitative PCTL, and we in fact conjecture the
opposite.">
Los Alamitos, California, 23rd IEEE Symposium on Logic in Computer Science (LICS 2008), 24-27 June 2008, Pittsburgh, USA, Proceedings, p. 391-402, 10 pp. 2008
Publisher
IEEE Computer Society
Other information
Language
English
Type of outcome
Stať ve sborníku
Field of Study
10201 Computer sciences, information science, bioinformatics
We study the satisfiability problem for qualitative PCTL (Probabilistic Computation Tree Logic), which is obtained from "ordinary" CTL by replacing the EX, AX, EU, and AU operators with their qualitative counterparts X>0, X=1, U>0, and U=1, respectively. As opposed to CTL, qualitative PCTL does not have a small model property, and there are even qualitative PCTL formulae which have only infinite-state models. Nevertheless, we show that the satisfiability problem for qualitative PCTL is EXPTIME-complete and we give an exponential-time algorithm which for a given formula computes a finite description of a model (if it exists), or answers "not satisfiable" (otherwise). We also consider the finite satisfiability problem and provide analogous results. That is, we show that the finite satisfiability problem for qualitative PCTL is EXPTIME-complete, and every finite satisfiable formula has a model of an exponential size which can effectively be constructed in exponential time. Finally, we give some results about the quantitative PCTL, where the numerical bounds in probability constraints can be arbitrary rationals between 0 and 1. We prove that the problem whether a given quantitative PCTL formula has a model of the branching degree at most k, where k > 1 is an arbitrary but fixed constant, is highly undecidable. We also show that every satisfiable formula F has a model with branching degree at most |F| + 2. However, this does not yet imply the undecidability of the satisfiability problem for quantitative PCTL, and we in fact conjecture the opposite.
In Czech
V článku je studován problém splnitelnosti pro kvalitativní fragment logiky PCTL. Oproti nepravděpodobnostnímu CTL nemá kvalitativní fragment PCTL vlastnost malého modelu a existují dokonce formule, které mají pouze nekonečné modely. V článku je ukázáno, že problém splnitelnosti pro kvalitativní fragment PCTL je EXPTIME-úplný a je podán exponenciální algoritmus, který pro danou formuli sestrojí konečný popis modelu je-li daná formule splnitelná. Je také uvažován problém konečné splnitelnosti a jsou prezentovány analogické výsledky jako v případě splnitelnosti.
Links
MSM0021622419, plan (intention)
Name: Vysoce paralelní a distribuované výpočetní systémy
Investor: Ministry of Education, Youth and Sports of the CR, Highly Parallel and Distributed Computing Systems
1M0545, research and development project
Name: Institut Teoretické Informatiky
Investor: Ministry of Education, Youth and Sports of the CR, Institute for Theoretical Computer Science
BRÁZDIL, Tomáš, Vojtěch FOREJT, Jan KŘETÍNSKÝ and Antonín KUČERA. The Satisfiability Problem for Probabilistic CTL. In 23rd IEEE Symposium on Logic in Computer Science (LICS 2008), 24-27 June 2008, Pittsburgh, USA, Proceedings. Los Alamitos, California: IEEE Computer Society, 2008, p. 391-402, 10 pp. ISBN 978-0-7695-3183-0.
@inproceedings{771768, author = {Brázdil, Tomáš and Forejt, Vojtěch and Křetínský, Jan and Kučera, Antonín}, address = {Los Alamitos, California}, booktitle = {23rd IEEE Symposium on Logic in Computer Science (LICS 2008), 24-27 June 2008, Pittsburgh, USA, Proceedings}, keywords = {Stochastic systems; branching-time temporal logics}, language = {eng}, location = {Los Alamitos, California}, isbn = {978-0-7695-3183-0}, pages = {391-402}, publisher = {IEEE Computer Society}, title = {The Satisfiability Problem for Probabilistic CTL}, year = {2008} }
TY - JOUR ID - 771768 AU - Brázdil, Tomáš - Forejt, Vojtěch - Křetínský, Jan - Kučera, Antonín PY - 2008 TI - The Satisfiability Problem for Probabilistic CTL PB - IEEE Computer Society CY - Los Alamitos, California SN - 9780769531830 KW - Stochastic systems KW - branching-time temporal logics N2 - We study the satisfiability problem for qualitative PCTL (Probabilistic Computation Tree Logic), which is obtained from "ordinary" CTL by replacing the EX, AX, EU, and AU operators with their qualitative counterparts X>0, X=1, U>0, and U=1, respectively. As opposed to CTL, qualitative PCTL does not have a small model property, and there are even qualitative PCTL formulae which have only infinite-state models. Nevertheless, we show that the satisfiability problem for qualitative PCTL is EXPTIME-complete and we give an exponential-time algorithm which for a given formula computes a finite description of a model (if it exists), or answers "not satisfiable" (otherwise). We also consider the finite satisfiability problem and provide analogous results. That is, we show that the finite satisfiability problem for qualitative PCTL is EXPTIME-complete, and every finite satisfiable formula has a model of an exponential size which can effectively be constructed in exponential time. Finally, we give some results about the quantitative PCTL, where the numerical bounds in probability constraints can be arbitrary rationals between 0 and 1. We prove that the problem whether a given quantitative PCTL formula has a model of the branching degree at most k, where k > 1 is an arbitrary but fixed constant, is highly undecidable. We also show that every satisfiable formula F has a model with branching degree at most |F| + 2. However, this does not yet imply the undecidability of the satisfiability problem for quantitative PCTL, and we in fact conjecture the opposite. ER -
BRÁZDIL, Tomáš, Vojtěch FOREJT, Jan KŘETÍNSKÝ and Antonín KUČERA. The Satisfiability Problem for Probabilistic CTL. In \textit{23rd IEEE Symposium on Logic in Computer Science (LICS 2008), 24-27 June 2008, Pittsburgh, USA, Proceedings}. Los Alamitos, California: IEEE Computer Society, 2008, p.~391-402, 10 pp. ISBN~978-0-7695-3183-0.