Representing Dependencies in Event Structures

TL;DR

This paper introduces a novel approach to event structures where context influences causality, emphasizing the role of modifiers in determining event dependencies and configurations, thus extending existing models.

Contribution

It proposes a new event structure model where context and modifiers determine causality, unifying various existing notions while highlighting the importance of contextual factors.

Findings

Most existing event structure notions can be translated into the new model.

The new model preserves the concept of configurations.

Context plays a central role in causality determination.

Abstract

Event structures where the causality may explicitly change during a computation have recently gained the stage. In this kind of event structures the changes in the set of the causes of an event are triggered by modifiers that may add or remove dependencies, thus making the happening of an event contextual. Still the focus is always on the dependencies of the event. In this paper we promote the idea that the context determined by the modifiers plays a major role, and the context itself determines not only the causes but also what causality should be. Modifiers are then used to understand when an event (or a set of events) can be added to a configuration, together with a set of events modeling dependencies, which will play a less important role. We show that most of the notions of Event Structure presented in literature can be translated into this new kind of event structure, preserving the main notion, namely the one of configuration.