The logic of events

An event space is a set of instantaneous events that vary both in time and specificity. The concept of an event space provides a foundation for a logical - i.e., modular and open - approach to causal reasoning. In this article, we propose intuitively transparent axioms for event spaces. These axioms are constructive in the intuitionistic sense, and hence they can be used directly for causal reasoning in any computational logical framework that accommodates type theory. We also put the axioms in classical form and show that in this form they are adequate for the representation in terms of event trees established by Shafer [40] using stronger axioms.