Abductive reasoning with temporal information

Texts in natural language contain a lot of temporal information, both explicit and implicit. Verbs and temporal adjuncts carry most of the explicit information, but for a full understanding general world knowledge and default assumptions have to be taken into account. We will present a theory for describing the relation between, on the one hand, verbs, their tenses and adjuncts and, on the other, the eventualities and periods of time they represent and their relative temporal locations, while allowing interaction with general world knowledge. The theory is formulated in an extension of rst order logic and is a practical implementation of the concepts described in Van Eynde (2001) and Schelkens et al. (2000). We will show how an abductive resolution procedure can be used on this representation to extract temporal information from texts. The theory presented here is an extension of that in Verdoolaege et al. (2000), adapted to Van Eynde (2001), with a simpli ed and extended analysis of adjuncts and with more emphasis on how a model can be constructed.