Time Representation and Use in Expert Systems

Resumé

The object of this report is to survey some of the uses and representations of time as it has been studied within the A.I. (artificial intelligence) community, especially within the expert systems subarea. In most applications the very concept of time is difficult to grasp. Therefore, we shall mention some of the philosophical ideas that have had importance in the A.I. literature.

One of our main theses is that there exist many levels of uses of time. In this report a rather broad range of papers are mentioned. In the conclusion we define degrees of ''understanding'' to distinguish different knowledge representations with respect to the ''depth'' of their use of time.