Finding Uniform Strategies for Multi-agent Systems

Electron. Proc. Theor. Comput. Sci.

2017

Since the introduction of Alternating-time Temporal Logic (AT L), many logics have been proposed to reason about different strategic capabilities of the agents of a system. In particular, some logics have been designed to reason about the uniform memoryless strategies of such agents. These strategies are the ones the agents can effectively play by only looking at what they observe from the current state. AT L ir can be seen as the core logic to reason about such uniform strategies. Nevertheless, its model-checking problem is difficult-it requires a polynomial number of calls to an NP oracle-, and practical algorithms to solve it appeared only recently.This paper proposes a technique for model checking uniform memoryless strategies. Existing techniques build the strategies from the states of interest-such as the initial states-through a forward traversal of the system. On the other hand, the proposed approach builds the winning strategies from the target states through a backward traversal, making sure that only uniform strategies are explored. Nevertheless, building the strategies from the ground up limits its applicability to constrained reachability objectives only. This paper describes the approach in details and compares it experimentally with existing approaches implemented into a BDD-based framework. These experiments show that the technique is competitive on the cases it can handle. * This research is financed by the Walloon Region as part of the Logistics in Wallonia competitiveness pole. 1 A ∆ P 2 problem requires a polynomial number of calls to an NP oracle.

Section: Resultsmentioning

confidence: 99%

A Backward-traversal-based Approach for Symbolic Model Checking of Uniform Strategies for Constrained Reachability

Electron. Proc. Theor. Comput. Sci.

2017

“…In this paper we presented AT LK F po , a logic combining partial observability and fairness constraints on states (which is the standard approach for temporal and epistemic logics), and we have provided a model checking algorithm.The proposed algorithm is similar to the one of Calta et al [3]. They also split possible actions into uniform strategies, but they do not provide a way to deal with fairness constraints.…”

Section: Resultsmentioning

confidence: 99%

Reasoning about Strategies under Partial Observability and Fairness Constraints

Electron. Proc. Theor. Comput. Sci.

et al. 2013

A number of extensions exist for Alternating-time Temporal Logic; some of these mix strategies and partial observability but, to the best of our knowledge, no work provides a unified framework for strategies, partial observability and fairness constraints. In this paper we propose ATLK^F_po, a logic mixing strategies under partial observability and epistemic properties of agents in a system with fairness constraints on states, and we provide a model checking algorithm for it

“…Finally, model checking uniform strategies has also been discussed by Calta et al [24]. Their approach is also based on splitting possible actions into uniform strategies, but their algorithm is tightly linked to the nature of the objectives, namely CTL-like objectives.…”

Section: Related Workmentioning

confidence: 97%

Reasoning about memoryless strategies under partial observability and unconditional fairness constraints

Information and Computation

et al. 2015

Alternating-time Temporal Logic is a logic to reason about strategies that agents can adopt to achieve a specified collective goal. A number of extensions for this logic exist; some of them combine strategies and partial observability, some others include fairness constraints, but to the best of our knowledge no work provides a unified framework for strategies, partial observability and fairness constraints. Integration of these three concepts is important when reasoning about the capabilities of agents without full knowledge of a system, for instance when the agents can assume that the environment behaves in a fair way. We present ATLK irF , a logic combining strategies under partial observability in a system with fairness constraints on states. We introduce a model-checking algorithm for ATLK irF by extending the algorithm for a full-observability variant of the logic and we investigate its complexity. We validate our proposal with an experimental evaluation.