Arbitrary Arrow Update Logic is a dynamic modal logic that uses an arbitrary arrow update modality to quantify over all arrow updates. Some properties of this logic have already been established, but until now it remained an open question whether the logic’s satisfiability problem is decidable. Here, we show that the satisfiability problem of Arbitrary Arrow Update Logic is co-RE hard, and ther...

One hundred and fifty years after the work of Ludwig Boltzmann on the interpretation of the irreversibility of physical phenomena, we are still not sure what we mean when we talk of “time” or the “arrow of time.” One source of this difficulty is our tendency to confuse time and becoming: that is, the course of time and the arrow of time, two concepts that the formalisms of physics do distinguis...

212 Figure 4b: T1W coronal post-gadolinium image just posterior to Meckel’s cave shows thickened right trigeminal nerve (black arrow) and enhancing extradural mass in middle cranial fossa (white arrow) Figure 4a: Contrast enhanced T1W coronal image shows enhancing intracranial extradural mass (black arrow) in the right middle cranial fossa with widened right foramen ovale (white arrow head) Fig...

A mathematical model of the flight of the arrow during its discharge from a bow was proposed by Pekalski (1990). His description of the model was incomplete. In this paper, I give a full description of the model. Furthermore, I propose some improvements that make his model more consistent with reality. One achievement is the modelling of contact of the arrow and grip; the pressure button is mod...

In this contribution we present arbitrary arrow update model logic (AAUML). This is a dynamic epistemic logic or update logic. In update logics, static/basic modalities are interpreted on a given relational model whereas dynamic/update modalities induce transformations (updates) of relational models. In AAUML the update modalities formalize the execution of arrow update models, and there is als...