We study term modal logics, where modalities can be indexed by variables that can be quantified over. We suggest that these logics are appropriate for reasoning about systems of unboundedly many reasoners and define a notion of bisimulation which preserves propositional fragment of term modal logics. Also we show that the propositional fragment is already undecidable but that its monodic fragment is decidable, and expressive enough to include interesting assertions.

Reasoning about equilibria in normal form games involves the study of players’ incentives to deviate unilaterally from any profile. In the case of large anonymous games, the pattern of reasoning is different. Payoffs are determined by strategy distributions rather than strategy profiles. In such a game each player would strategise based on expectations of what fraction of the population makes some choice, rather than respond to individual choices by other players. A player may not even know how many players there (...) are in the game. Logicising such strategisation involves many challenges as the set of players is potentially unbounded. This suggests a logic of quantification over player variables and modalities for player deviation, but such a logic is easily seen to be undecidable. Instead, we propose a propositional modal logic using player types as names and implicit quantification over players. With modalities for player deviation and transitive closure, the logic can be used to specify game equilibrium and interesting patterns of reasoning in large games. We show that the logic is decidable and present a complete axiomatisation of the valid formulas. (shrink)

In large anonymous games, payoffs are determined by strategy distributions rather than strategy profiles. If half the players choose a strategy a, all of them get a certain payoff, whereas if only one-third of the players choose that strategy, the players choosing may get a different payoff. Strategizing in such a game by a player involves reasoning about not who does what but what fraction of the population makes the same choice as that player.We present a simple modal logic to (...) reason about such strategization in large games. Since actual numbers are irrelevant, a player need not even know how many others are in the game, thus leading to the consideration of games with unboundedly many players. The logic we consider is the propositional modal fragment of a first order modal logic. We show that it has a bounded agent property, giving us a decision procedure for satisfiability. We also present a complete axiomatization of the valid formulas. The logic admits a natural model checking algorithm and bisimulation characterization. The logic with quantification over players is more appropriate, but is undecidable. (shrink)

Although we think 1 of the basic purposes of journalism is to provide information vital to enhancing citizen autonomy, we also see this goal as being in direct tension with the power news media hold and wield, power that may serve to undercut, rather than enhance, citizen autonomy. We argue that the news media are ethically constrained by proceduralism, resulting in journalists asserting power inappropriately at the individual level, and unwittingly surrendering moral authority institutionally and globally. Anonymity, institutionalization, and routinization (...) cloak power relationships among citizens, journalists and the institutions of which they are a part, ultimately inculcating these distinctly Western values in the global community. (shrink)

This paper is about the good side of modal logic, the bad side of modal logic, and how hybrid logic takes the good and fixes the bad.In essence, modal logic is a simple formalism for working with relational structures . But modal logic has no mechanism for referring to or reasoning about the individual nodes in such structures, and this lessens its effectiveness as a representation formalism. In their simplest form, hybrid logics are upgraded modal logics in which reference to (...) individual nodes is possible.But hybrid logic is a rather unusual modal upgrade. It pushes one simple idea as far as it will go: represent all information as formulas. This turns out to be the key needed to draw together a surprisingly diverse range of work . Moreover, it displays a number of knowledge representation issues in a new light, notably the importance of sorting. (shrink)

Rid and Wendler propose the development of a Patient Preference Predictor (PPP), an actuarial model for predicting incapacitated patient’s life-sustaining treatment preferences across a wide range of end-of-life scenarios. An actuarial approach to end-of-life decision making has enormous potential, but transferring the logic of actuarial prediction to end-of-life decision making raises several conceptual complexities and logistical problems that need further consideration. Actuarial models have proven effective in targeted prediction tasks, but no evidence supports their effectiveness in the kind of broad (...) spectrum prediction task that is the proposed goal of the PPP. We argue that a more focused approach, targeting specific medical conditions and generating treatment predictions based on the preferences of individuals with actual disease experience, is both more firmly grounded in past research and is a more prudent initial strategy for exploring the efficacy of actuarial prediction in end-of-life decision making. (shrink)

A modified Beltrametti-Cassinelli-Lahti model of the measurement apparatus that satisfies both the probability reproducibility condition and the objectification requirement is constructed. Only measurements on microsystems are considered. The cluster separability forms a basis for the first working hypothesis: the current version of quantum mechanics leaves open what happens to systems when they change their separation status. New rules that close this gap can therefore be added without disturbing the logic of quantum mechanics. The second working hypothesis is that registration apparatuses (...) for microsystems must contain detectors and that their readings are signals from detectors. This implies that the separation status of a microsystem changes during both preparation and registration. A new rule that specifies what happens when these changes occur and that guarantees the objectification is formulated and discussed. A part of our result has certain similarities with ‘collapse of the wave function’. (shrink)

We investigate the Sp(2, R) model for light and heavy nuclei and compare it to recent applications of the Sp(6, R) model. The same Hamiltonian is used and the basis states will have good angular momentum. We not only confirm that the restricted space of the Sp(6, R) model gives the dominant contribution but also that there is no practical difference from the Sp(6, R) model calculations. The Sp(2, R) model is then applied to the chain of Ba-isotopes which show, (...) according to a recent application of the geometrical model, a dominant prolate behavior with an important γ-unstable component. They represent limiting cases where the Sp(2, R) model can be put to an extreme test. (shrink)

For live-related kidney donation, the current UK guidance specifies that the donor has a right to know the recipient’s HIV status. This guidance may prevent some potential recipients from asking friends or family to donate, as they do not wish them to know they are HIV positive. Currently, it is felt necessary that the donor should know the HIV status of the recipient in order to give fully informed consent to the operation. However, the specific medical details are not required (...) in order to allow for donor informed consent. This consent requires knowledge of the general expectation for survival of a graft and the specific expectation for survival of this graft in the recipient; it does not require specific knowledge of the recipient’s medical condition. (shrink)