Temporal reasoning based on semi-intervals

摘要

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.