Two Ways to Common Knowledge

TitleTwo Ways to Common Knowledge
Publication TypeConference Paper
Year of Publication2010
AuthorsBucheli, S, Kuznets, R, Studer, T
EditorBolander, T, Braüner, T
Conference NameProceedings of the 6th Workshop on Methods for Modalities (M4M–6 2009), Copenhagen, Denmark, 12–14 November 2009
Keywordsproof theory
AbstractIt is not clear what a system for evidence-based common knowledge should look like if common knowledge is treated as a greatest fixed point. This paper is a preliminary step towards such a system. We argue that the standard induction rule is not well suited to axiomatize evidence-based common knowledge. As an alternative, we study two different deductive systems for the logic of common knowledge. The first system makes use of an induction axiom whereas the second one is based on co-inductive proof theory. We show the soundness and completeness for both systems.