Temporal reasoning based on semi-intervals

A generalization of Allen's interval-based approach to temporal reasoning is presented, with the notion of ‘conceptual neighborhood’ of qualitative relations between events is central and knowledge about relations between events can be represented much more compactly.

Abstract

A generalization of Allen's interval-based approach to temporal reasoning is presented. The notion of 'conceptual neighborhood' of qualitative relations between events is central to the presented approach. Relations between semi-intervals rather than intervals are used as the basic units of knowledge. Semi-intervals correspond to temporal beginnings or endings of events. We demonstrate the advantages of reasoning on the basis of semi-intervals: (1) semi-intervals are rather natural entities both from a cognitive and from a computational point of view; (2) coarse knowledge can be processed directly; computational effort is saved; (3) incomplete knowledge about events can be fully exploited; (4) incomplete inferences made on the basis of complete knowledge can be used directly for further inference steps; (5) there is no trade-off in computational strength for the added flexibility and efficiency; (6) for a natural subset of Allen's algebra, global consistency can be guaranteed in polynomial time; (7) knowledge about relations between events can be represented much more compactly.