---
title: "Time for Action: On the Relation Between Time, Knowledge and Action"
authors:
  - "Yoav Shoham"
doi: ""
url: "https://ijcai.org/proceedings/1989/153"
pdf: "https://ijcai.org/proceedings/1989/0153.pdf"
venue: "Proceedings of the Eleventh International Joint Conference on Artificial Intelligence"
year: 1989
pages: "954-958"
track: "Planning, Scheduling, Reasoning About Actions"
keywords:
---

# Time for Action: On the Relation Between Time, Knowledge and Action

Yoav Shoham

*Proceedings of the Eleventh International Joint Conference on Artificial Intelligence*, pages 954-958.

## Abstract

We consider the role played by the concept of action in AI. We first briefly summarize the advantages and limitations of past approaches to taking the concept as primitive, as embodied in the situation calculus and dynamic logic. We also b_riefty summarize the alternative, namely ~doptmg a temporal framework, and point out Its complementary advantages and limitations. We then propose a framework that retains the advantages of both viewpoints, and that ties the notion of action closely to that of knowledge. Specifically, we propose starting with the notion of time lines, and defining the notion of action as the ability to make certain choices among sets of time lines. Our definitions shed new light on the connection between time ac-. , t10n, knowledge and ignorance, choice-making, feasibility, and simultaneous reasoning about the same events at different levels of detail.