Papers by Laurent Perrussel
Journal of Logic and Computation
In this paper, we present two models for reasoning about strategic actions in opinion diffusion. ... more In this paper, we present two models for reasoning about strategic actions in opinion diffusion. In both models, the agents are endowed with goals expressed compactly in a suitably defined language of linear temporal logic and are connected in an influence network which defines the underlying opinion diffusion process. The agents can act by exerting their influence or retain from it: in one case, we assume an initial state of incomplete information about the agents’ opinions, while in the other, we assume that the agents have complete information. We investigate the interplay between simple network structures (e.g. certain acyclic graphs) and the existence of game-theoretic solution concepts for the unanimity aggregator. We also give bounds for the computational complexity of strategic reasoning in both our models on arbitrary networks.
Most existing models of opinion diffusion on networks neglect the existence of logical constraint... more Most existing models of opinion diffusion on networks neglect the existence of logical constraints that might correlate individual opinions on multiple issues. In this paper we study the diffusion of constrained opinions on a social network as an iterated process of aggregating neighbouring opinions. Individual views are modelled as vectors of yes/no answers to a number of propositions subject to integrity constraints, and each individual updates her opinion by looking at the aggregated opinion of her influencers. To overcome the problem of updating towards inconsistent influencing opinions, we propose a model based on individual updates on subsets of the issues of limited size called propositionwise updates. By adapting notions from the theory of boolean functions, we identify classes of integrity constraints on which propositionwise updates decrease the influence gap between nodes of the network and their influencers caused by the presence of an integrity constraint. Furthermore, ...
In online advertising, search engines sell ad placements for keywords continuously through auctio... more In online advertising, search engines sell ad placements for keywords continuously through auctions. This problem can be seen as an infinitely repeated game since the auction is executed whenever a user performs a query with the keyword. As advertisers may frequently change their bids, the game will have a large set of equilibria with potentially complex strategies. In this paper, we propose the use of natural strategies for reasoning in such setting as they are processable by artificial agents with limited memory and/or computational power as well as understandable by human users. To reach this goal, we introduce a quantitative version of Strategy Logic with natural strategies in the setting of imperfect information. In a first step, we show how to model strategies for repeated keyword auctions and take advantage of the model for proving properties evaluating this game. In a second step, we study the logic in relation to the distinguishing power, expressivity, and model-checking co...
Le Centre pour la Communication Scientifique Directe - HAL - Grenoble Ecole de Management, May 4, 2015
Le Centre pour la Communication Scientifique Directe - HAL - Inria, May 4, 2015
We present a formal model of opinion diffusion and formation which combines notions from social n... more We present a formal model of opinion diffusion and formation which combines notions from social network analysis together with concepts and techniques from judgment aggregation and merging. The model allows us to study the propagation of individual opinions, represented in the form of yes/no answers to a set of multiple binary issues, in a multiagent system linked by an influence network. The process is iterative with discrete time. We are interested in characterizing properties of the network structure which guarantee convergence of the iterative process for every initial configuration of the agents' opinions, and in developing tractable algorithms for computing the set of opinions at convergence.
Artificial Intelligence, 2021
Introduction Syntax and Semantics Epistemic and Strategic Reasoning Model Checking Conclusions Ou... more Introduction Syntax and Semantics Epistemic and Strategic Reasoning Model Checking Conclusions Outline 1 Introduction 2 Syntax and Semantics 3 Epistemic and Strategic Reasoning 4 Model Checking 5 Conclusions 2/30 Introduction Syntax and Semantics Epistemic and Strategic Reasoning Model Checking Conclusions Background: General Game Playing (GGP) AI programs are able to play more than one games successfully. 3/30 Introduction Syntax and Semantics Epistemic and Strategic Reasoning Model Checking Conclusions General Game Player Systems able to understand the rules of previously unknown games. able to learn to play these games well without human intervention. 4/30 Introduction Syntax and Semantics Epistemic and Strategic Reasoning Model Checking Conclusions Official Languages General Game Description Language (GDL) machine-processable logical language for representing the rules of arbitrary finite games [Love et al., 2006]. GDL-II for imperfect information games describe any extensive-form game with randomness and imperfect information [Thielscher, 2011]. Introduction Syntax and Semantics Epistemic and Strategic Reasoning Model Checking Conclusions Motivation Challenge Playing games with imperfect information poses an intricate reasoning challenge for players. GDL-II is purely a game descriptive language but does not provide a reasoning facility.
Logics in Artificial Intelligence, 2021
In this paper, we investigate strategic reasoning in the context of auctions. More precisely, we ... more In this paper, we investigate strategic reasoning in the context of auctions. More precisely, we establish an explicit link between bidding actions and bounded rationality. To do so, we extend the Auction Description Language with an epistemic operator and an action choice operator and use it to represent a classical auction where agents have imperfect information about other agents' valuations. We formalize bounded rationality concepts in iterative protocols and show how to use them to reason about the players' actions. Finally, we provide a model checking algorithm.
Proceedings of the Twenty-Sixth International Joint Conference on Artificial Intelligence, 2017
We extend hierarchical task network planning with task insertion (TIHTN) by introducing state con... more We extend hierarchical task network planning with task insertion (TIHTN) by introducing state constraints, called TIHTNS. We show that just as for TIHTN planning, all solutions of the TIHTNS planning problem can be obtained by acyclic decomposition and task insertion, entailing that its plan-existence problem is decidable without any restriction on decomposition methods. We also prove that the extension by state constraints does not increase the complexity of the plan-existence problem, which stays 2-NEXPTIME-complete, based on an acyclic progression operator. In addition, we show that TIHTNS planning covers not only the original TIHTN planning but also hierarchy-relaxed hierarchical goal network planning.
The goal of this paper is to propose a framework for representing and reasoning about the rules g... more The goal of this paper is to propose a framework for representing and reasoning about the rules governing a combinatorial exchange. Such a framework is at first interest as long as we want to build up digital marketplaces based on auction, a widely used mechanism for automated transactions. Combinatorial exchange is the most general case of auctions, mixing the double and combinatorial variants: agents bid to trade bundles of goods. Hence the framework should fulfill two requirements: (i) it should enable bidders to express their bids on combinations of goods and (ii) it should allow describing the rules governing some market, namely the legal bids, the allocation and payment rules. To do so, we define a logical language in the spirit of the Game Description Language: the Combinatorial Exchange Description Language is the first language for describing combinatorial exchange in a logical framework. The contribution is two-fold: first, we illustrate the general dimension by representi...
The goal of this paper is to propose a language for representing and reasoning about the rules go... more The goal of this paper is to propose a language for representing and reasoning about the rules governing an auction-based market. Such language is at first interest as long as we want to build up digital market places based on auction, a widely used framework for automated transactions. Auctions may differ in several aspects: single or double-side, ascending or descending, single or multi-unit, open cry or sealed-bid, and so on. This variety prevents an agent to easily switch between different (auction-based) markets. The first requirement for building such agents is to have a general language for describing auction-based markets. Second, this language should also allow the reasoning about the key issues of a specific market, namely the allocation and payment rules. To do so, we define a language in the spirit of the Game Description Language (GDL): the Auction Description Language (ADL) is the first language for describing auctions in a logical framework. In this paper, we illustra...
Dynamics, Uncertainty and Reasoning, 2019
We provide a logical analysis of Dung's abstract argumentation frameworks and their dynamics. We ... more We provide a logical analysis of Dung's abstract argumentation frameworks and their dynamics. We express attack relation and argument status by means of propositional variables and define acceptability criteria by formulas of propositional logic, which enables us to formulate the standard reasoning problems in logic. While the approaches in the literature express these problems as boolean or quantified boolean formulas, we here take advantage of a variant of Propositional Dynamic Logic PDL: Dynamic Logic of Propositional Assignments DL-PA, whose atomic programs are assignments of propositional variables to truth values. One of the benefits is that algorithms computing extensions of argumentation frameworks can be viewed as particular DL-PA programs. This allows us to formally prove the correctness of these algorithms. Another benefit is that in the same logic we can also design and study programs which modify argumentation frameworks. Indeed, the basic operations on these propositional variables, viz. change of the truth values of the attack variables and the argument status variables, are nothing but atomic programs of DL-PA. We mainly focus on how the acceptance of one or more arguments can be enforced and show how this can be achieved by changing the truth values of the propositional variables describing the attack relation in a minimal way.
Proceedings of the Eighteenth International Conference on Principles of Knowledge Representation and Reasoning, 2021
Mechanism Design aims at defining mechanisms that satisfy a predefined set of properties, and Auc... more Mechanism Design aims at defining mechanisms that satisfy a predefined set of properties, and Auction Mechanisms are of foremost importance. Core properties of mechanisms, such as strategy-proofness or budget-balance, involve: (i) complex strategic concepts such as Nash equilibria, (ii) quantitative aspects such as utilities, and often (iii) imperfect information,with agents’ private valuations. We demonstrate that Strategy Logic provides a formal framework fit to model mechanisms, express such properties, and verify them. To do so, we consider a quantitative and epistemic variant of Strategy Logic. We first show how to express the implementation of social choice functions. Second, we show how fundamental mechanism properties can be expressed as logical formulas,and thus evaluated by model checking. Finally, we prove that model checking for this particular variant of Strategy Logic can be done in polynomial space.
Proceedings of the AAAI Conference on Artificial Intelligence, 2020
Hierarchical Task Network (HTN) planning is showing its power in real-world planning. Although do... more Hierarchical Task Network (HTN) planning is showing its power in real-world planning. Although domain experts have partial hierarchical domain knowledge, it is time-consuming to specify all HTN methods, leaving them incomplete. On the other hand, traditional HTN learning approaches focus only on declarative goals, omitting the hierarchical domain knowledge. In this paper, we propose a novel learning framework to refine HTN methods via task insertion with completely preserving the original methods. As it is difficult to identify incomplete methods without designating declarative goals for compound tasks, we introduce the notion of prioritized preference to capture the incompleteness possibility of methods. Specifically, the framework first computes the preferred completion profile w.r.t. the prioritized preference to refine the incomplete methods. Then it finds the minimal set of refined methods via a method substitution operation. Experimental analysis demonstrates that our approach...
Electronic Proceedings in Theoretical Computer Science, 2017
In the typical framework for boolean games (BG) each player can change the truth value of some pr... more In the typical framework for boolean games (BG) each player can change the truth value of some propositional atoms, while a empting to make her goal true. In standard BG goals are propositional formulas, whereas in iterated BG goals are formulas of Linear Temporal Logic. Both notions of BG are characterised by the fact that agents have exclusive control over their set of atoms, meaning that no two agents can control the same atom. In the present contribution we drop the exclusivity assumption and explore structures where an atom can be controlled by multiple agents. We introduce Concurrent Game Structures with Shared Propositional Control (CGS-SPC) and show that they account for several classes of repeated games, including iterated boolean games, in uence games, and aggregation games. Our main result shows that, as far as verication is concerned, CGS-SPC can be reduced to concurrent game structures with exclusive control. is result provides a polynomial reduction for the model checking problem of speci cations in Alternating-time Temporal Logic on CGS-SPC.
Computational Intelligence, 2017
Judgment aggregation deals with the problem of how collective judgments on logically connected pr... more Judgment aggregation deals with the problem of how collective judgments on logically connected propositions can be formed based on individual judgments on the same propositions. The existing literature on judgment aggregation mainly focuses on the anonymity condition requiring that individual judgments be treated equally. However, in many real-world situations, a group making collective judgments may assign individual members or subgroups different priorities to determine the collective judgment. Based on this consideration, this paper relaxes the anonymity condition by giving a hierarchy over individuals so as to investigate how the judgment from each individual affects the group judgment in such a hierarchical environment. Moreover, we assume that an individual can abstain from voting on a proposition and the collective judgment on a proposition can be undetermined, which means that we do not require completeness at both individual and collective levels. In this new setting, we first identify an impossibility result and explore a set of plausible conditions in terms of abstentions. Secondly, we develop an aggregation rule based on the hierarchy of individuals and show that the aggregation rule satisfies those plausible conditions. The computational complexity of this rule is also investigated. Finally, we show that the proposed rule is (weakly) oligarchic over a subset of agenda. This is by no means a negative result. In fact, our result reveals that with abstentions, oligarchic aggregation is not necessary to be a single-level determination but can be a multiple-level collective decision-making, which partially explains its ubiquity in the real world.
Lecture Notes in Computer Science, 2016
According to Bratman, future-directed intentions are highlevel plans. We view such plans as high-... more According to Bratman, future-directed intentions are highlevel plans. We view such plans as high-level actions that can typically not be executed directly: they have to be progressively refined until executable basic actions are obtained. Higher-and lower-level actions are linked by the means-end relation, alias instrumentality relation. In this paper we extend Shoham's database perspective of Bratman's theory by the notions of refinement and instrumentality.
International Journal of Approximate Reasoning, 2017
Any decision taken by an agent requires some knowledge of its environment. Communication with oth... more Any decision taken by an agent requires some knowledge of its environment. Communication with other agents is a key issue for assessing the overall quality of its own knowledge. This assessment is a challenge itself as the agent may receive information from unknown agents. The aim of this paper is to propose a framework for assessing the reliability of unknown agents based on communication. We assume that information is represented through logical statements and logical inconsistency is the underlying notion of reliability assessment. In our context, assessing consists of ranking the agents and representing reliability through a total preorder. The overall communication set is first evaluated with the help of inconsistency measures. Next, the measures are used for assessing the contribution of each agent to the overall inconsistency of the communication set. After stating the postulates specifying the expected properties of the reliability preorder, we show through a representation theorem how these postulates and the contribution of the agent are interwoven. We also detail how the properties of the inconsistency measures influence the properties of the contribution assessment. Finally we describe how to aggregate different reliability preorders, each of them may be based on different inconsistency measures.
Lecture Notes in Computer Science, 2015
This paper addresses the question of assessing the relative reliability of unknown information so... more This paper addresses the question of assessing the relative reliability of unknown information sources. We propose to consider a phase during which the consistency of information they report is analysed, whether it is the consistency of each single report, or the consistency of a report w.r.t. some trusted knowledge or the consistency of different reports together. We adopt an axiomatic approach by first giving postulates which characterize how the resulting reliability preorder should be; then we define a family of operators for building this preorder and demonstrate that it satisfies the proposed postulates.
Lecture Notes in Computer Science, 2014
This paper presents a logical framework that extends the Game Description Language with coalition... more This paper presents a logical framework that extends the Game Description Language with coalition operators from Alternatingtime Temporal Logic and prioritised strategy connectives. Our semantics is built upon the standard state transition model. The new framework allows us to formalise van Benthem's game-oriented principles in multiplayer games, and formally derive Weak Determinacy and Zermelo's Theorem for two-player games. We demonstrate with a real-world game how to use our language to specify a game and design a strategy, and how to use our framework to verify a winning/no-losing strategy. Finally, we show that the model-checking problem of our logic is in 2EXPTIME with respect to the size of game structure and the length of formula, which is no worse than the model-checking problem in ATL ⋆ .
Logic, Rationality, and Interaction, 2017
The Game Description Language (GDL) has been introduced as an official language for specifying ga... more The Game Description Language (GDL) has been introduced as an official language for specifying games in the AAAI General Game Playing Competition since 2005. It was originally designed as a declarative language for representing rules of arbitrary games with perfect information. More recently, an epistemic extension of GDL, called EGDL, has been proposed for representing and reasoning about imperfect information games. In this paper, we develop an axiomatic system for a variant of EGDL and prove its soundness and completeness with respect to the semantics based on the epistemic state transition model. With a combination of action symbols, temporal modalities and epistemic operators, the completeness proof requires novel combinations of techniques used for completeness of propositional dynamic logic and epistemic temporal logic. We demonstrate how to use the proof theory for inferring game properties from game rules.
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Papers by Laurent Perrussel