Intelligence in Strategic Games

An agent, or a coalition of agents, faces an ethical dilemma between several statements if she is forced to make a conscious choice between which of these statements will be true. This paper proposes to capture ethical dilemmas as a modality in strategic game settings with and without limit on sacrifice and for perfect and imperfect information games. The authors show that the dilemma modality cannot be defined through the earlier proposed blameworthiness modality. The main technical result is a sound and complete axiomatization of the properties of this modality with sacrifice in games with perfect information.

The paper studies strategic abilities that rise from restrictions on the information sharing in multi-agent systems. The main technical result is a sound and complete logical system that describes the interplay between the knowledge and the strategic ability modalities.

The paper investigates the second-order blameworthiness or duty to warn modality "one coalition knew how another coalition could have prevented an outcome''. The main technical result is a sound and complete logical system that describes the interplay between the distributed knowledge and the duty to warn modalities.

This paper presents a sound and complete logical system whose atomic sentences are the equalities of recursive terms involving sets. There are two interpretations of this language: one makes use of non-wellfounded sets with finite transitive closure, and the other uses pointed finite graphs modulo bisimulation. Our logical system is a sequent-style deduction system. The main axioms and inference rules come from the $\mbox{{\it FLR}$_0$}$ -proof system from [6], including the Recursion Inference Rule (but an additional axiom is needed), and also axioms corresponding to the extensionality axiom of set theory.

The article proposes a new approach to reasoning about knowledge and strategies in multiagent systems. It emphasizes data, not agents, as the source of strategic knowledge. The approach brings together Armstrong's functional dependency expression from database theory, a data-informed knowledge modality based on a recent work by Baltag and van Benthem, and a newly proposed data-informed strategy modality. The main technical result is a sound and complete logical system that describes the interplay between these three logical operators.

The author introduces a temporal logic called interval division logic, IDL, based on the constructive temporal ontology. In IDL, time is regarded as a constructive object which is built from an interval by iterating the interval division every time a new temporal fact is recognized. IDL as a sound and complete logical system which is as expressive as the Buich tree automata. In order to examine how the persistence problem is treated on this ontology, the author extends a nonmonotonic version of IDL based on the model preference in which any belief is changed as late as possible in the epistemological order rather than the temporal order. The Yale shooting problem is discussed in this framework.

Along with the convenience brought by the increasing usage of autonomous systems, unexpected accidents happened. These accidents emphasize the need for autonomous systems to possess the ability to recognize potential hazards, effectively communicate these hazards to human operators, and facilitate retrospective analyses. This ability, including recognition, prejudgment, post-analysis, and reasoning, falls within the realm of cognitive ability, which is important in improving the safety and outcomes in the decision-making process of such systems. In this paper, we present a foundational step toward addressing the safety challenges involving the cognitive ability of artificial agents. We study the interplay between knowledge and the cognitive ability of intelligent agents. The main technical result is a sound and complete bimodal logical system that describes the interplay between the knowledge and cognitive ability modalities.

Together we know how to achieve: An epistemic logic of know-how

Digital platforms, ecosystems, and Research&Development-intensive industries challenge conventional, one-shot merger control. In fast-evolving markets, competitive constraints and innovation trajectories can shift after clearance, while behavioral commitments – often imposed for long durations – are exposed to obsolescence, moral hazard during implementation, and adverse selection rooted in imperfect information at notification. We propose a conceptual model of adaptive merger control that introduces structured ex post flexibility through a review clause attached to conditional clearance. The clause can be activated within a predefined window when observable triggers indicate that the original package has become ineffective or disproportionate. We outline governance options for initiation by authorities, merging parties, or affected stakeholders; information tools for dynamic counterfactuals; and a continuum of remedy designs distinguishing fixed commitments, adaptable behavioral remedies, and regulation-like constraints. The framework highlights two symmetric enforcement errors – excessive restraint and excessive precaution – and shows how adaptive design can mitigate both while preserving legal certainty via transparent procedures and bounded discretion. We discuss implementation challenges, including monitoring capacity, strategic gaming, and the potential transition from behavioral to structural measures. The article provides a framework for remedy design in dynamic markets and for the assessment of merger chains in digital and innovation markets.

Cooperation in a differentiated duopoly when information is dispersed: A beauty contest game with endogenous concern for coordination

This paper presents a logical system in which various group-level epistemic actions are incorporated into the object language. That is, we consider the standard modeling of knowledge among a set of agents by multi-modal Kripke structures. One might want to consider actions that take place, such as announcements to groups privately, announcements with suspicious outsiders, etc. In our system, such actions correspond to additional modalities in the object language. That is, we do not add machinery on top of models (as in Fagin et al [1], but we reify aspects of the machinery in the logical language. The first case of the kind of logics we consider appears in Gerbrandy and Groeneveld [3]. They introduced a language in which one can faithfully represent all of the reasoning in examples such as the Muddy Children scenario. In that paper we find operators for updating worlds via announcements to groups of agents who are isolated from all others. We advance this by considering many more actions; and by using a more general semantics. Our logic contains the infinitary operators used in the standard modeling of common knowledge. We present a sound and complete logical system for the logic, and we study its expressive power.

This work considers linear precoding strategies for multiple-input single-out (MISO) interference channels with channel mean feedback at transmitters, where the interference at each receiver is treated as additive noise. The challenge here is that previous precoder designs with perfect channel state information (CSI) at transmitters do not apply and new approaches are required. Based on the Laplace transform order, an altruistic non-equilibrium strategy, i.e., the stochastic zero forcing, is first proposed under practical assumptions, generalizing the traditional zero forcing which requires perfect CSI. Interestingly, the precoding matrices here are all rank-one beamformers as in the traditional zero forcing. The competitive use of the common physical media in MISO interference channels is also formulated as a strategic noncooperative game. In contrast to the perfect CSI case with a unique rank-one Nash equilibrium, with channel mean feedback, the Nash equilibria here are not necessarily rank-one in general. Nevertheless, when achieved by the rank-one beamforming, the equilibrium is unique and convenient for implementation. Accordingly, the condition for beamforming to achieve the equilibrium is derived. Comparisons of the above two strategies reveal no overall dominance of one over the other, thereby establishing stochastic zero forcing as an alternative to the Nash equilibrium designs.

The notion of interchangeability has been introduced by John Nash in one of his original papers on equilibria. This paper studies properties of Nash equilibria interchangeability in cellular games that model behavior of infinite chain of homogeneous economic agents. The paper shows that there are games in which a strategy of any given player is interchangeable with strategies of players in an arbitrary large neighborhood of the given player, but is not interchangeable with the strategy of a remote player outside of the neighborhood. The main technical result is a sound and complete logical system describing universal properties of interchangeability common to all cellular games.

20 Modal logic for games and information

Applications of Soft Computing to Human-centered Information Systems