Instantaneous Events

Antony Galton

In Hans Jürgen Ohlbach (editor), Temporal Logic: Proceedings of the ICTL Workshop, Max-Planck-Institut für Informatik, technical report MPI-I-94-230, June 1994, pages 4-11.

Abstract

We distinguish strictly instantaneous events, which have zero duration, from momentary events which have a positive duration that is in some sense minimal. We further classify events, insofar as their occurrence conditions can be given in terms of the holding or not holding of states, into transitions, which are characterised in terms of the states holding immediately before and after the event, and tenures, which are characterised in terms of a state holding when the event actually happens, but neither immediately before nor after it. These categories are considered in relation to both continuous and discrete models of time. Precise occurrence conditions are given for all events arising from these considerations, using Allen's well-known interval calculus, extended to allow reference to instants. In addition, the concept of dominance is introduced to furnish a criterion for whether or not a given qualitative event type admits instantaneous occurrences. We further consider the possibility of temporal models that are neither continuous nor discrete, instancing as examples Allen and Hayes' moments and Russell's account of the relation between the psychological subjective present and an underlying physical time continuum.

Read the paper (Postscript file, 13 pages)