This paper reports on the development of DILEMMA-2*, a lemmatizer-tagger for the sublanguage of medical abstracts. The program is an extension of DILEMMA-I, a lemmatizertagger for general English texts. In the first section a brief outline is given of DILEMMA-1. Particular attention _is paid to the original concept of a default category which is linked with a categorial graph by means of a poin...

We analyze in...nitely repeated prisoners’ dilemma games with imperfect private monitoring, and construct sequential equilibria where strategies are measurable with respect to players’ beliefs regarding their opponents’ continuation strategies. We show that, when monitoring is almost perfect, the symmetric e¢cient outcome can be approximated in any prisoners’ dilemma game, while every individua...

Recently, the authors proposed a quantum prisoner's dilemma game based on the spatial game of Nowak and May, and showed that the game can be played classically. By using this idea, we proposed three generalized prisoner's dilemma (GPD, for short) games based on the weak Prisoner's dilemma game, the full prisoner's dilemma game and the normalized Prisoner's dilemma game, written by GPDW, GPDF an...

A new game system formalism is presented. The system describes both strategies and game master (who computes scores of a given game system) in terms of λ-calculus. A prisoner’s dilemma game is revisited with this formalism, to discuss how meta-strategies emerge in this classical game even without repetition. The present results show that Howard’s meta-game hierarchy is realizable in terms of λ-...

Individuals in a committee can increase their voting power by forming coalitions. This behavior is shown here to yield a prisoner’s dilemma, in which a subset of voters can increase their power, while reducing average voting power for the electorate as a whole. This is an unusual form of the prisoner’s dilemma in that cooperation is the selfish act that hurts the larger group. Under a simple mo...

We investigate the behavior or males and females in an experimental Prisoner’s Dilemma game with a partisan audience. In each session, there are two same-gender groups, either both male, both female, or one group of males and one group of females. Groups are separated into two rooms; each period, the Prisoner’s Dilemma is played in each room. One player from the other room is seated across a ta...

Two players engaged in the Prisoner’s Dilemma have to choose between cooperation and defection, the pay-off of the players is determined by a weight w=(T ,R ,P ,S ) . For deterministic strategies p 1 ,... , p n we consider a society S=S( u i : p i∣ i=1 ,... ,n) formed by individuals playing at random the IPD with weight w . We introduce the concept of a w -successful society as one where all in...

We study the transition towards effective payoffs in the prisoner’s dilemma game on scale-free networks by introducing a normalization parameter guiding the system from accumulated payoffs to payoffs normalized with the connectivity of each agent. We show that during this transition the heterogeneity-based ability of scalefree networks to facilitate cooperative behavior deteriorates continuousl...

When players in a game can communicate they may learn each other’s strategy. It is then natural to define a player’s strategy as a mapping from what he has learned about the other players’ strategies into actions. In this paper we investigate the consequences of this possibility in two-player games and show that it expands the set of equilibrium outcomes in one-shot games. When strategies are o...

We propose a methodology that is generalizable to a broad class of repeated games in order to facilitate operability of belief learning models with repeated-game strategies. The methodology consists of (1) a generalized repeated-game strategy space, (2) a mapping between histories and repeated-game beliefs, and (3) asynchronous updating of repeated-game strategies. We implement the proposed met...