2,214 research outputs found
On the Complexity of ATL and ATL* Module Checking
Module checking has been introduced in late 1990s to verify open systems,
i.e., systems whose behavior depends on the continuous interaction with the
environment. Classically, module checking has been investigated with respect to
specifications given as CTL and CTL* formulas. Recently, it has been shown that
CTL (resp., CTL*) module checking offers a distinctly different perspective
from the better-known problem of ATL (resp., ATL*) model checking. In
particular, ATL (resp., ATL*) module checking strictly enhances the
expressiveness of both CTL (resp., CTL*) module checking and ATL (resp. ATL*)
model checking. In this paper, we provide asymptotically optimal bounds on the
computational cost of module checking against ATL and ATL*, whose upper bounds
are based on an automata-theoretic approach. We show that module-checking for
ATL is EXPTIME-complete, which is the same complexity of module checking
against CTL. On the other hand, ATL* module checking turns out to be
3EXPTIME-complete, hence exponentially harder than CTL* module checking.Comment: In Proceedings GandALF 2017, arXiv:1709.0176
Module Checking of Pushdown Multi-agent Systems
In this paper, we investigate the module-checking problem of pushdown multi-agent systems (PMS) against ATL and ATL* specifications. We establish that for ATL, module checking of PMS is 2EXPTIME-complete, which is the same complexity as pushdown module-checking for CTL. On the other hand, we show that ATL* module-checking of PMS turns out to be 4EXPTIME-complete, hence exponentially harder than both CTL* pushdown module-checking and ATL* model-checking of PMS. Our result for ATL* provides a rare example of a natural decision problem that is elementary yet but with a complexity that is higher than triply exponential-time
Module checking of pushdown multi-agent systems
In this paper, we investigate the module-checking problem of pushdown
multi-agent systems (PMS) against ATL and ATL* specifications. We establish
that for ATL, module checking of PMS is 2EXPTIME-complete, which is the same
complexity as pushdown module-checking for CTL. On the other hand, we show that
ATL* module-checking of PMS turns out to be 4EXPTIME-complete, hence
exponentially harder than both CTL* pushdown module-checking and ATL*
model-checking of PMS. Our result for ATL* provides a rare example of a natural
decision problem that is elementary yet but with a complexity that is higher
than triply exponential-time.Comment: arXiv admin note: substantial text overlap with arXiv:1709.0210
Alternating-time temporal logic with finite-memory strategies
Model-checking the alternating-time temporal logics ATL and ATL* with
incomplete information is undecidable for perfect recall semantics. However,
when restricting to memoryless strategies the model-checking problem becomes
decidable. In this paper we consider two other types of semantics based on
finite-memory strategies. One where the memory size allowed is bounded and one
where the memory size is unbounded (but must be finite). This is motivated by
the high complexity of model-checking with perfect recall semantics and the
severe limitations of memoryless strategies. We show that both types of
semantics introduced are different from perfect recall and memoryless semantics
and next focus on the decidability and complexity of model-checking in both
complete and incomplete information games for ATL/ATL*. In particular, we show
that the complexity of model-checking with bounded-memory semantics is
Delta_2p-complete for ATL and PSPACE-complete for ATL* in incomplete
information games just as in the memoryless case. We also present a proof that
ATL and ATL* model-checking is undecidable for n >= 3 players with
finite-memory semantics in incomplete information games.Comment: In Proceedings GandALF 2013, arXiv:1307.416
Model-checking Quantitative Alternating-time Temporal Logic on One-counter Game Models
We consider quantitative extensions of the alternating-time temporal logics
ATL/ATLs called quantitative alternating-time temporal logics (QATL/QATLs) in
which the value of a counter can be compared to constants using equality,
inequality and modulo constraints. We interpret these logics in one-counter
game models which are infinite duration games played on finite control graphs
where each transition can increase or decrease the value of an unbounded
counter. That is, the state-space of these games are, generally, infinite. We
consider the model-checking problem of the logics QATL and QATLs on one-counter
game models with VASS semantics for which we develop algorithms and provide
matching lower bounds. Our algorithms are based on reductions of the
model-checking problems to model-checking games. This approach makes it quite
simple for us to deal with extensions of the logical languages as well as the
infinite state spaces. The framework generalizes on one hand qualitative
problems such as ATL/ATLs model-checking of finite-state systems,
model-checking of the branching-time temporal logics CTL and CTLs on
one-counter processes and the realizability problem of LTL specifications. On
the other hand the model-checking problem for QATL/QATLs generalizes
quantitative problems such as the fixed-initial credit problem for energy games
(in the case of QATL) and energy parity games (in the case of QATLs). Our
results are positive as we show that the generalizations are not too costly
with respect to complexity. As a byproduct we obtain new results on the
complexity of model-checking CTLs in one-counter processes and show that
deciding the winner in one-counter games with LTL objectives is
2ExpSpace-complete.Comment: 22 pages, 12 figure
Model checking coalitional games in shortage resource scenarios
Verification of multi-agents systems (MAS) has been recently studied taking
into account the need of expressing resource bounds. Several logics for
specifying properties of MAS have been presented in quite a variety of
scenarios with bounded resources. In this paper, we study a different
formalism, called Priced Resource-Bounded Alternating-time Temporal Logic
(PRBATL), whose main novelty consists in moving the notion of resources from a
syntactic level (part of the formula) to a semantic one (part of the model).
This allows us to track the evolution of the resource availability along the
computations and provides us with a formalisms capable to model a number of
real-world scenarios. Two relevant aspects are the notion of global
availability of the resources on the market, that are shared by the agents, and
the notion of price of resources, depending on their availability. In a
previous work of ours, an initial step towards this new formalism was
introduced, along with an EXPTIME algorithm for the model checking problem. In
this paper we better analyze the features of the proposed formalism, also in
comparison with previous approaches. The main technical contribution is the
proof of the EXPTIME-hardness of the the model checking problem for PRBATL,
based on a reduction from the acceptance problem for Linearly-Bounded
Alternating Turing Machines. In particular, since the problem has multiple
parameters, we show two fixed-parameter reductions.Comment: In Proceedings GandALF 2013, arXiv:1307.416
Contrasting dedicated model transformation languages versus general purpose languages: a historical perspective on ATL versus Java based on complexity and size
Model transformations are among the key concepts of model-driven engineering (MDE), and dedicated model transformation languages (MTLs) emerged with the popularity of the MDE pssaradigm about 15 to 20 years ago. MTLs claim to increase the ease of development of model transformations by abstracting from recurring transformation aspects and hiding complex semantics behind a simple and intuitive syntax. Nonetheless, MTLs are rarely adopted in practice, there is still no empirical evidence for the claim of easier development, and the argument of abstraction deserves a fresh look in the light of modern general purpose languages (GPLs) which have undergone a significant evolution in the last two decades. In this paper, we report about a study in which we compare the complexity and size of model transformations written in three different languages, namely (i) the Atlas Transformation Language (ATL), (ii) Java SE5 (2004–2009), and (iii) Java SE14 (2020); the Java transformations are derived from an ATL specification using a translation schema we developed for our study. In a nutshell, we found that some of the new features in Java SE14 compared to Java SE5 help to significantly reduce the complexity of transformations written in Java by as much as 45%. At the same time, however, the relative amount of complexity that stems from aspects that ATL can hide from the developer, which is about 40% of the total complexity, stays about the same. Furthermore we discovered that while transformation code in Java SE14 requires up to 25% less lines of code, the number of words written in both versions stays about the same. And while the written number of words stays about the same their distribution throughout the code changes significantly. Based on these results, we discuss the concrete advancements in newer Java versions. We also discuss to which extent new language advancements justify writing transformations in a general purpose language rather than a dedicated transformation language. We further indicate potential avenues for future research on the comparison of MTLs and GPLs in a model transformation context.Universität Ulm (1055)Peer Reviewe
Parity-energy ATL for Qualitative and Quantitative Reasoning in MAS
In this paper, we introduce a new logic suitable to reason about strategic
abilities of multi-agent systems where (teams of) agents are subject to
qualitative (parity) and quantitative (energy) constraints and where goals are
represented, as usual, by means of temporal properties.
We formally define such a logic, named parity-energy-atl (peatl, for short),
and we study its model checking problem, which we prove to be decidable with
different complexity upper bounds, depending on different choices for the
energy range
Modularity and Openness in Modeling Multi-Agent Systems
We revisit the formalism of modular interpreted systems (MIS) which
encourages modular and open modeling of synchronous multi-agent systems. The
original formulation of MIS did not live entirely up to its promise. In this
paper, we propose how to improve modularity and openness of MIS by changing the
structure of interference functions. These relatively small changes allow for
surprisingly high flexibility when modeling actual multi-agent systems. We
demonstrate this on two well-known examples, namely the trains, tunnel and
controller, and the dining cryptographers.
Perhaps more importantly, we propose how the notions of multi-agency and
openness, crucial for multi-agent systems, can be precisely defined based on
their MIS representations.Comment: In Proceedings GandALF 2013, arXiv:1307.416
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