Natural Factors of the Medvedev Lattice Capturing IPC

Skvortsova showed that there is a factor of the Medvedev lattice which captures intuitionistic propositional logic (IPC). However, her factor is unnatural in the sense that it is constructed in an ad hoc manner. We present a more natural example of such a factor. We also show that for every non-trivial factor of the Medvedev lattice its theory is contained in Jankov's logic, the deductive closure of IPC plus the weak law of the excluded middle. This answers a question by Sorbi and Terwijn

The Ethics of Resisting Deportation

Can anti-deportation resistance be justified, and if so how and by whom may, or perhaps should, unjust deportations be resisted? In this paper, I seek to provide an answer to these questions. The paper starts by describing the main forms and agents of anti-deportation action in the contemporary context. Subsequently, I examine how different justifications for principled resistance and disobedience may each be invoked in the case of deportation resistance. I then explore how worries about the resister’s motivation for engaging in the action and their epistemic position apply in the specific context of anti-deportation action and consider in what circumstances there is not merely a right but a duty to resist deportation. The upshot of this argument, I conclude, is that the liberal state ought to respond to anti-deportation action not by criminalising disobedience and resistance in this field, but rather by creating legal avenues for such actors to influence deportation decision-making. DOI 10.17879/95189423213

Maximal R-symmetry violating amplitudes in type IIB superstring theory

On-shell superspace techniques are used to quantify R-symmetry violation in type IIB superstring theory amplitudes in a flat background in ten dimensions. This shows the existence of a particularly simple class of non-vanishing amplitudes in this theory which violate R-symmetry maximally. General properties of the class and some of its extensions are established which at string tree level are shown to determine the first three non-trivial effective field theory contributions to all multiplicity. This leads to a natural conjecture for the exact analytic part of the first two of these.Comment: 10 pages. minute modifications, references adde

Meetings in smart environments : implications of progressing technology

Meetings are often inefficiënt. They are numerous and unavoidable. If we look at the technological developments in this area we quickly see that along with the introduction of the microphone and the data projector, the execution of a meeting for the participants has become much easier. Yet there are still many aspects of a meeting that can be improved, where technology in its current stage has not contributed much. There is for instance hardly any technology that is able to autonomously interpret, or analyze, aspects of the meeting process. An automatic analysis of a meeting could provide valuable insights for both the attendants, as well as for those interested parties who could not attend.\ud These insights hypothetically could in turn lead again to more successful meeting processes. It is, for example, often the case that one or two dominant participants can monopolize a complete meeting in a way that they make it impossible for others to contribute. Another example is that the argumentation that has been put forward and that led to a certain decision is often forgotten and lost, not to mention that during a discussion just one line of argumentation can be in the center of attention.\ud It is investigated to what extent the latest technological developments can provide automatic insights into both, so-called higher-level meeting phenomena. To enable the automatic recognition, a descriptive and computationally accessible model has been created for the phenomenon of dominance hierarchy as well as for argument structure. Whereas the model for a dominance hierarchy did not require more than a ranking of the participants, the model that describes the argumentation structure requires interpretation of the individual contributions, as well as the knowledge of how to label contributions in the context of the discussion