Logic and Games Event

October 26, 2000
Hotel Dennenhoeve
Nunspeet


During the school week of the Dutch Research School in Nunspeet,
the Logic in Communication project organizes an afternoon on Logic and Games
For more information, contact Paul Dekker or Yde Venema

Program


Titles and Abstracts

Erik Krabbe: Hamblin's and Lorenzen's Systems of Dialogue: Comparison and Integration

>From the perspective of theory of argumentation, two desirable features of dialogue systems (or, dialogue games) are the following: the sytems should be realistic, i.e. descriptively accurate, and they should have normative bite, i.e. they should provide a normative basis for argument criticism. But these two features do not go together very well. After a brief introduction to Hamblin-type (H-type) and to Lorenzen-type (L-type) systems of dialogue, it will be discussed to what extent such systems display these two, and other, desirable features. Next, it will be shown how L-dialogues can be embedded into H-dialogues to yield a system that combines the best of both.



Henry Prakken: The use of games in modelling argumentation

This talk reviews the use of games in formal models of argumentation. Two, related topics are discussed:
1. Game-theoretic formulations of nonmonotonic consequence relations
In the study of defeasible reasoning the game form has been used to formulate nonmonotonic consequence notions. Inference is modelled as a dispute between a proponent and opponent of a proposition, who exchange arguments for and against it. The proposition follows if the proponent has a winning strategy for it.
2. Dialogue games for argumentation.
In recent years, dialogue systems for argumentation have received interest in several fields of computer science and artificial intelligence, such as discourse generation, multi-agent systems, intelligent tutoring, and AI and law. Argumentative dialogue systems regulate the use of such speech acts as making, challenging, conceding or withdrawing a claim, and arguing for or against a claim. The game form has been used to formalise such dialogue systems, and to clarify their relation with logics for defeasible reasoning.

Marco Vervoort: Blackwell Games

My lecture is about the problem of determinacy of Blackwell games, a class of infinite games of imperfect information, where both players simultaneously select moves from a finite set, infinitely many rounds are played, and payoff is determined by a Borel measurable function $f$ on the set of possible resulting sequences of moves. For general Borel payoff functions, we give a reduction, found by D.A. Martin, to the known result of determinacy of Borel perfect information games. We also consider Blackwell games whose payoff function is not Borel measurable, and formulate an analogue of the Axiom of Determinacy for these games, Finally, we compare some of the consequences of this `Axiom of Blackwell Determinacy' with those of the original Axiom of Determinacy.

Samson Abramsky: Title to be announced





Yde Venema