Chapter 19 - Temporal CSPs

Abstract

This chapter explores that temporal reasoning is an area that has greatly benefited by the application of techniques from constraint programming. Temporal constraint satisfaction problems (CSPs) have been proved to be a robust framework. Specific results about temporal CSPs have often provided the motivation for deriving general results about CSPs. Temporal CSPs have been studied in depth, not only because of intellectual curiosity, but mostly because of their importance for applications such as planning, scheduling, temporal databases and others mentioned above. In many cases, the problems studied come straight from the application front and developed solutions are immediately put into practical use. The chapter also introduces the most influential temporal reasoning formalisms based on constraint networks that have been proposed in the literature and relevant algorithmic problems. It introduces the scheme of indefinite constraint databases that is, up to today, the most comprehensive proposal for querying hybrid representations consisting of a relational database component and a constraint network component. In the case of temporal CSPs, the constraint network can be used to store temporal constraints on various temporal objects, and the relational database to store facts referring to these objects.