Graph Theoretic Models for Reasoning About Time

Abstract

Reasoning about time is a very ancient discipline, perhaps as old as prehistoric man. These ancient humans had discovered how long to roast their hunted meat and how to dry and age the skins of animals. They learned how and when to plant seeds, and were guided by the cycles of the sun, moon and the seasons. Our ancestors knew that day followed night and night followed day, and they had some notion of duration of day and night. This basic temporal knowledge was exploited to develop a sense of planning, taking advantage of observation and experience. For example, they would have observed that deer drink at the river at a certain time of the day, or that .sh are easier to catch in the early morning. Early humans could recognize the changing seasons, and adapted their behavior in order to expect and avoid some of the dangers of cold and hunger by preparing in advance.

This paper was written in honor of Jean-Louis Lassez with whom the author has often engaged in discussion on reasoning about time, and was supported in part by the IRST Trento – CRI Haifa Cooperation Project.