Third edition of Artificial Intelligence: foundations of computational agents, Cambridge University Press, 2023 is now available (including the full text).
14.1 Planning with Individuals and Relations
An agent's goals and its environment are often described in terms of individuals and relations. When the agent's knowledge base is built, and before the agent knows the objects it should reason about, it requires a representation that is independent of the individuals. Thus, it must go beyond feature-based representations. When the individuals become known, it is possible to ground out the representations in terms of features. Often, it is useful to reason in terms of the non-grounded representations.
With a relational representation, we can reify time. Time can be represented in terms of individuals that are points in time or temporal intervals. This section presents two relational representations that differ in how time is reified.
