To describe the experts' knowledge about durations of different events, Allen has proposed a formalism based on time intervals. One of the main problems with this formalism is that some events are really instantaneous; to describe these events, we need points; in principle, one can describe points in terms of intervals, but this description is somewhat clumsy and complicated. To solve this problem, Galton has proposed to add points to Allen's formalism. Still, since the original (Allen's) formalism was interval-oriented, in Galton's formalism, intervals are still easier to describe and to handle than points.
In the paper under review, the authors propose a new formalism in which both intervals and points are basic objects, easy to describe and easy to handle.