A logic for global and local announcements
File(s)
Published version
Author(s)
Belardinelli, F
Van Ditmarsch, H
Van Der Hoek, W
Type
Conference Paper
Abstract
© F. Belardinelli, H. van Ditmarsch & W. van der Hoek. In this paper we introduce global and local announcement logic (GLAL), a dynamic epistemic logic with two distinct announcement operators - [Φ]+A and [Φ]-A indexed to a subset A of the set Ag of all agents - for global and local announcements respectively. The boundary case [Φ]+Ag corresponds to the public announcement of Φ, as known from the literature. Unlike standard public announcements, which are model transformers, the global and local announcements are pointed model transformers. In particular, the update induced by the announcement may be different in different states of the model. Therefore, the resulting computations are trees of models, rather than the typical sequences. A consequence of our semantics is that modally bisimilar states may be distinguished in our logic. Then, we provide a stronger notion of bisimilarity and we show that it preserves modal equivalence in GLAL. Additionally, we show that GLAL is strictly more expressive than public announcement logic with common knowledge. We prove a wide range of validities for GLAL involving the interaction between dynamics and knowledge, and show that the satisfiability problem for GLAL is decidable. We illustrate the formal machinery by means of detailed epistemic scenarios.
Date Issued
2017-07-25
Date Acceptance
2017-07-24
Citation
Electronic Proceedings in Theoretical Computer Science, EPTCS, 2017, 251, pp.28-42
ISSN
2075-2180
Start Page
28
End Page
42
Journal / Book Title
Electronic Proceedings in Theoretical Computer Science, EPTCS
Volume
251
Copyright Statement
©F. Belardinelli, H. van Ditmarsch & W. van der HoekThis work is licensed under theCreative Commons Attribution License.
Source
16th Conference on Theoretical Aspects of Rationality and Knowledge (TARK)
Subjects
Science & Technology
Technology
Computer Science, Theory & Methods
Computer Science
COMPLETENESS
COMPLEXITY
KNOWLEDGE
Publication Status
Published
Start Date
2017-07-24
Coverage Spatial
Liverpool, UK
Date Publish Online
2017-07-24