tailieunhanh - Báo cáo khoa học: ""REFERENCE TO LOCATIONS"

We propose a semantics for locative expressions such as near Jones or west of Denver, an important subsystem for NLP applications. Locative expressions denote regions of space, and serve as arguments to predicates, locating objects and events spatially. Since simple locatives occupy argument positions, they do NOT participate in scope ambiguities m pace one common view, which sees locatives as logical operators. Our proposal justifies common representational practice in computational linguistics, accounting for how locative expressions function anaphoritally, and explaining a wide range of inference involving locatives. . | REFERENCE TO LOCATIONS Lewis G. Creary J. Mark Gawron and John Nerbonne Hewlett-Packard Laboratories 3U 1501 Page Mill Road Palo Alto CA 94304-1126 Abstract We propose a semantics for locative expressions such as near Jones or west of Denver an important subsystem for NLP applications. Locative expressions denote regions of space and serve as arguments to predicates locating objects and events spatially. Since simple locatives occupy argument positions they do NOT participate in scope ambiguities pace one common view which sees locatives as logical operators. Our proposal justifies common representational practice in computational linguistics accounting for how locative expressions function anaphorically and explaining a wide range of inference involving locatives. We further demonstrate how the argument analysis may accommodate multiple locative arguments in a single predicate. The analysis is implemented for use in a database query application. 1 Introduction Locative expressions take diverse forms in New York here there nowhere and on a boat he has in Ohio. They combine with common nouns city on the Rhine or with verbs or verb-phrases work in Boston always locating objects and situations in space. Some temporal expressions are similar but we focus here on spatial locatives. The analysis was developed for use in an NLP system producing database queries it is fully implemented and has been in frequent developmental use for 18 months. It is important to provide facilities for reasoning about location in database query applications because users typically do not query locative information in the exact form it appears in the database. Â database may . contain the information that a painting is in the Guggenheim Museum perhaps even that it s in the Guggenheim in New York and yet be helpless when queried whether that same painting is in the US. In our implementation information about location is represented using the logical analysis provided 1 Of course the