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 logi cal - i.e., modular and open - approach to causal reasoning. In this articl e, we propose intuitively transparent axioms for event spaces. These axioms are constructive in the intuitionistic sense, and hence they can be used d irectly for causal reasoning in any computational logical framework that ac commodates type theory. We also put the axioms in classical form and show t hat in this form they are adequate for the representation in terms of event trees established by Shafer [40] using stronger axioms.