August 2009 Update: Final version is available here. July 2009 Update: This paper has been accepted by the JLC. March 2009 Update: The Journal of Logic and Computation (JLC) has sent us back the reviews, and we need a revision before it gets accepted.

Joint work with Wiebe van der Hoek and Michael Wooldridge. Published in the Proceedings of Workshop on Logic, Rationality and Interaction (LORI07), Beijing, August 2007. PDF Download: Strategy Logics and the Game Description Language. Any comments are welcome! ABSTRACT: The Game Description Language (GDL) is a special purpose declarative language for defining games. GDL is [...]

This is a joint work with H. P. VAN DITMARSCH and R. VERBRUGGE. PDF Download: Sum and Product in Dynamic Epistemic Logic Abstract: The Sum-and-Product riddle was first published in the reference H. Freudenthal (1969, Nieuw Archief voor Wiskunde 3, 152) [6].We provide an overview on the history of the dissemination of this riddle through [...]

This is a joint work with Professor Jan van Eijck(CWI, Netherlands), and Tomasz Sadzik(Stanford, USA). It was presented in Games, action and social software Workshop , 30 Oct – 3 Nov 2006 @ Lorentz Center, Leiden, the Netherlands. A pre-publication version is open for download: Action Emulation. Abstract: The effects of public announcements, private communications, [...]

Authors: H.P. van Ditmarsch, J. Ruan, and W. van der Hoek Abstract: We give a relation between a logic of knowledge and change, with a semantics on Kripke models, and a logic of knowledge and time, with a semantics on interpreted systems. More in particular, given an epistemic state (pointed multi-agent Kripke model where all [...]

Authors: Hans van Ditmarsch and Ji Ruan Résumé : Dans les puzzles épistémiques les annonces d’ignorance, ou des séquences de tels annonces, souvent résultent en connaissances. Nous présentons le puzzle ‘Quelle Somme ?’, et le modèlisent dans la logique des annonces publiques – un langage logique avec des opérateurs dynamiques et épistémiques. La solution du [...]