scholarly journals Learning What Others Know

10.29007/plm4 ◽  
2020 ◽  
Author(s):  
Alexandru Baltag ◽  
Sonja Smets

We propose a number of powerful dynamic-epistemic logics for multi-agent information sharing and acts of publicly or privately accessing other agents’ information databases. The static base of our logics is obtained by adding to standard epistemic logic comparative epistemic assertions for groups or individuals, as well as a common distributed knowledge operator (that combines features of both common knowledge and distributed knowledge). On the dynamic side, we introduce actions by which epistemic superiority can be acquired: “sharing all one knows” (by e.g. giving access to one’s information database to all or some of the other agents), as well as more complex informational events, such as hacking. We completely axiomatize several such logics and prove their decidability.

Author(s):  
Andreas Herzig ◽  
Antonio Yuste Ginel

We introduce a multi-agent, dynamic extension of abstract argumentation frameworks (AFs), strongly inspired by epistemic logic, where agents have only partial information about the conflicts between arguments. These frameworks can be used to model a variety of situations. For instance, those in which agents have bounded logical resources and therefore fail to spot some of the actual attacks, or those where some arguments are not explicitly and fully stated (enthymematic argumentation). Moreover, we include second-order knowledge and common knowledge of the attack relation in our structures (where the latter accounts for the state of the debate), so as to reason about different kinds of persuasion and about strategic features. This version of multi-agent AFs, as well as their updates with public announcements of attacks (more concretely, the effects of these updates on the acceptability of an argument) can be described using S5-PAL, a well-known dynamic-epistemic logic. We also discuss how to extend our proposal to capture arbitrary higher-order attitudes and uncertainty.


2011 ◽  
Vol 4 (4) ◽  
pp. 536-559 ◽  
Author(s):  
BARTELD KOOI ◽  
BRYAN RENNE

We presentArrow Update Logic, a theory of epistemic access elimination that can be used to reason about multi-agent belief change. While the belief-changing “arrow updates” of Arrow Update Logic can be transformed into equivalent belief-changing “action models” from the popular Dynamic Epistemic Logic approach, we prove that arrow updates are sometimes exponentially more succinct than action models. Further, since many examples of belief change are naturally thought of from Arrow Update Logic’s perspective of eliminating access to epistemic possibilities, Arrow Update Logic is a valuable addition to the repertoire of logics of information change. In addition to proving basic results about Arrow Update Logic, we introduce a new notion of common knowledge that generalizes both ordinary common knowledge and the “relativized” common knowledge familiar from the Dynamic Epistemic Logic literature.


2020 ◽  
Vol 23 (65) ◽  
pp. 1-18
Author(s):  
Levan Uridia ◽  
Dirk Walther

We investigate the variant of epistemic logic S5 for reasoning about knowledge under hypotheses. The logic is equipped with a modal operator of necessity that can be parameterized with a hypothesis representing background assumptions. The modal operator can be described as relative necessity and the resulting logic turns out to be a variant of Chellas’ Conditional Logic. We present an axiomatization of the logic and its extension with the common knowledge operator and distributed knowledge operator. We show that the logics are decidable, complete w.r.t. Kripke as well as topological structures. The topological completeness results are obtained by utilizing the Alexandroff connection between preorders and Alexandroff spaces.


2018 ◽  
Vol 29 (7) ◽  
pp. 1041-1069 ◽  
Author(s):  
Thomas Ågotnes ◽  
Natasha Alechina

Abstract Coalition logic is currently one of the most popular logics for multi-agent systems. While logics combining coalitional and epistemic operators have received considerable attention, completeness results for epistemic extensions of coalition logic have so far been missing. In this paper we provide several such results and proofs. We prove completeness for epistemic coalition logic with common knowledge, with distributed knowledge, and with both common and distributed knowledge, respectively. Furthermore, we completely characterise the complexity of the satisfiability problem for each of the three logics. We also study logics with interaction axioms connecting coalitional ability and knowledge.


1937 ◽  
Vol 10 (1) ◽  
pp. 158-163
Author(s):  
W. Langenbeck ◽  
H. C. Rhiem

Abstract The catalytic power of organic compounds in general has up to the present time been studied much less extensively than that of inorganic compounds. For about the last ten years, however, the first author has, in collaboration with a number of his students, attempted to fill this gap, though so far efforts have been confined to explaining the mode of action of natural enzymes by means of comparative experiments with organic catalysts. As a result of this work, a theory based on experimental facts has been developed to explain in a satisfactory way the action of enzymes. The other phase of organic catalysis is, strictly speaking, a technical problem. Why for instance should it not be practicable to utilize organic catalysts more extensively than heretofore in industry? If this problem is to be attacked, it seems reasonable to start with the particular industry which already uses organic catalysts to the greatest extent. This is, of course, the rubber industry. The important accomplishments of the chemical industry with respect to the development of vulcanization accelerators is already common knowledge, and the important task at present is not simply to increase the great number of accelerators already known. A problem of more practical value would seem to be to study the mechanism of the acceleration of vulcanization, about which relatively little has been known heretofore.


2010 ◽  
Vol 26 (3) ◽  
pp. 345-367 ◽  
Author(s):  
Olivier Roy

In this paper I study intentions of the form ‘I intend that we . . .’, that is, intentions with a we-content, and their role in interpersonal coordination. I focus on the notion of epistemic support for such intentions. Using tools from epistemic game theory and epistemic logic, I cast doubt on whether such support guarantees the other agents' conditional mediation in the achievement of such intentions, something that appears important if intentions with a we-content are to count as genuine intentions. I then formulate a stronger version of epistemic support, one that does indeed ensure the required mediation, but I then argue that it rests on excessively strong informational conditions. In view of this I provide an alternative set of conditions that are jointly sufficient for coordination in games, and I argue that these conditions constitute a plausible alternative to the proposed notion of epistemic support.


Author(s):  
Hang Ma ◽  
Glenn Wagner ◽  
Ariel Felner ◽  
Jiaoyang Li ◽  
T. K. Satish Kumar ◽  
...  

We formalize Multi-Agent Path Finding with Deadlines (MAPF-DL). The objective is to maximize the number of agents that can reach their given goal vertices from their given start vertices within the deadline, without colliding with each other. We first show that MAPF-DL is NP-hard to solve optimally. We then present two classes of optimal algorithms, one based on a reduction of MAPF-DL to a flow problem and a subsequent compact integer linear programming formulation of the resulting reduced abstracted multi-commodity flow network and the other one based on novel combinatorial search algorithms. Our empirical results demonstrate that these MAPF-DL solvers scale well and each one dominates the other ones in different scenarios.


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