scholarly journals Relativized common knowledge for dynamic epistemic logic

2015 ◽  
Vol 13 (3) ◽  
pp. 370-393 ◽  
Author(s):  
Yì N. Wáng ◽  
Thomas Ågotnes
Keyword(s):  
Epistemic Logic ◽  
Common Knowledge ◽  
Dynamic Epistemic Logic

scholarly journals Playing cards with Hintikka An introduction to dynamic epistemic logic

2005 ◽  
Vol 3 ◽  
Author(s):  
H. P. Ditmarsch ◽  
W. Van Der Hoek ◽  
B. P. Kooi
Keyword(s):  
Epistemic Logic ◽  
Common Knowledge ◽  
Dynamic Epistemic Logic ◽  
Knowledge And Beliefs ◽  
Public Announcements

This contribution is a gentle introduction to so-called dynamic epistemic logics, that can describe how agents change their knowledge and beliefs. We start with a concise introduction to epistemic logic, through the example of one, two and finally three players holding cards; and, mainly for the purpose of motivating the dynamics, we also very summarily introduce the concepts of general and common knowledge. We then pay ample attention to the logic of public announcements, wherein agents change their knowledge as the result of public announcements. One crucial topic in that setting is that of unsuccessful updates: formulas that become false when announced. The Moore-sentences that were already extensively discussed at the conception of epistemic logic in Hintikka’s ‘Knowledge and Belief ’ (1962) give rise to such unsuccessful updates. After that, we present a few examples of more complex epistemic updates.

scholarly journals Multi-Agent Abstract Argumentation Frameworks With Incomplete Knowledge of Attacks

2021 ◽  
Author(s):  
Andreas Herzig ◽  
Antonio Yuste Ginel
Keyword(s):  
Epistemic Logic ◽  
Partial Information ◽  
Common Knowledge ◽  
Higher Order ◽  
Dynamic Epistemic Logic ◽  
Second Order ◽  
The State ◽  
Incomplete Knowledge ◽  
Abstract Argumentation ◽  
Multi Agent

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.

scholarly journals ARROW UPDATE LOGIC

2011 ◽  
Vol 4 (4) ◽  
pp. 536-559 ◽  
Author(s):  
BARTELD KOOI ◽  
BRYAN RENNE
Keyword(s):  
Epistemic Logic ◽  
Belief Change ◽  
Common Knowledge ◽  
Dynamic Epistemic Logic ◽  
Epistemic Access ◽  
Multi Agent ◽  
Logic Approach ◽  
Action Models ◽  
Information Change ◽  
Update Logic

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.

scholarly journals THE EXPRESSIVITY OF FACTUAL CHANGE IN DYNAMIC EPISTEMIC LOGIC

2013 ◽  
Vol 7 (2) ◽  
pp. 208-221 ◽  
Author(s):  
LOUWE B. KUIJER
Keyword(s):  
Epistemic Logic ◽  
Common Knowledge ◽  
Dynamic Epistemic Logic ◽  
Public Announcements

AbstractA commonly used dynamic epistemic logic is one obtained by adding commonknowledge and public announcements to a basic epistemic logic. It is known from Kooi (2007) that adding public substitutions to such a logic adds expressivity over the class K of models. Here I show that substitutions also add expressivity over the classes KD45, S4 and S5 of models. Since the combination of common knowledge, public announcements and substitutions, was shown in Kooi (2007) to be equally expressive to relativized common knowledge these results also show that relativized common knowledge is more expressive than common knowledge and public announcements over KD45, S4 and S5. These results therefore extend the result from van Benthem et al. (2006) that shows that relativized common knowledge is more expressive than common knowledge and public announcements over K.

scholarly journals Small Undecidable Problems in Epistemic Planning

2018 ◽  
Author(s):  
Sébastien Lê Cong ◽  
Sophie Pinchinat ◽  
François Schwarzentruber
Keyword(s):  
Cellular Automata ◽  
Epistemic Logic ◽  
Common Knowledge ◽  
Dynamic Epistemic Logic ◽  
Planning Problem ◽  
Reachability Problem ◽  
Public Action ◽  
Automatic Structure ◽  
The Common ◽  
Initial Knowledge

Epistemic planning extends classical planning with knowledge and is based on dynamic epistemic logic (DEL). The epistemic planning problem is undecidable in general. We exhibit a small undecidable subclass of epistemic planning over 2-agent S5 models with a fixed repertoire of one action, 6 propositions and a fixed goal. We furthermore consider a variant of the epistemic planning problem where the initial knowledge state is an automatic structure, hence possibly infinite. In that case, we show the epistemic planning problem with 1 public action and 2 propositions to be undecidable, while it is known to be decidable  with public actions over finite models. Our results are obtained by reducing the reachability problem over small universal cellular automata. While our reductions yield a goal formula that displays the common knowledge operator, we show, for each of our considered epistemic problems, a reduction into an epistemic planning problem for a common-knowledge-operator-free goal formula by using 2 additional actions.

scholarly journals Converging on Common Knowledge

2019 ◽  
Author(s):  
Dominik Klein ◽  
Rasmus Kræmmer Rendsvig
Keyword(s):  
Epistemic Logic ◽  
Finite Time ◽  
Common Knowledge ◽  
Communication Protocols ◽  
Dynamic Epistemic Logic

Common knowledge, as is well known, is not attainable in finite time by unreliable communication, thus hindering perfect coordination. Focusing on the coordinated attack problem modeled using dynamic epistemic logic, this paper discusses unreliable communication protocols from a topological perspective and asks "If the generals may communicate indefinitely, will they then *converge* to a state of common knowledge?" We answer by making precise and showing the following: *common knowledge is attainable if, and only if, we do not care about common knowledge*.

Topo-Logic as a Dynamic-Epistemic Logic

2017 ◽  
pp. 330-346 ◽  
Author(s):  
Alexandru Baltag ◽  
Aybüke Özgün ◽  
Ana Lucia Vargas Sandoval
Keyword(s):  
Epistemic Logic ◽  
Dynamic Epistemic Logic

scholarly journals The Dynamic Epistemic Logic for Actual Knowledge

2020 ◽  
Vol 49 (1) ◽  
Author(s):  
Arkadiusz Wójcik
Keyword(s):  
Epistemic Logic ◽  
Dynamic Epistemic Logic ◽  
Logical Omniscience ◽  
Actual Knowledge ◽  
Knowledge Change ◽  
The Past ◽  
Knowledge Models ◽  
Complete Axiomatization ◽  
New Information

The dynamic epistemic logic for actual knowledge models the phenomenon of actual knowledge change when new information is received. In contrast to the systems of dynamic epistemic logic which have been discussed in the past literature, our system is not burdened with the problem of logical omniscience, that is, an idealized assumption that the agent explicitly knows all classical tautologies and all logical consequences of his or her knowledge. We provide a sound and complete axiomatization for this logic.

Sign in / Sign up

Export Citation Format

Share Document