tailieunhanh - Báo cáo khoa học: "The detection and representation of ambiguities of intension and description"

Ambiguities related to intension and their consequent inference failures are a diverse group, both syntactically and semantically. One particular kind of ambiguity t h a t has received little attention so far is whether it is the speaker or the third p a r t y to whom a description in an opaque third-party attitude report should be attributed. The different readings lead to different inferences in a system modeling the beliefs of external agents. We propose t h a t a unified approach to the representation of the alternative readings of intension-related ambiguities can be based on the. | The detection and representation of ambiguities of intension and description Brenda Fawcett and Graeme Hirst Department of Computer Science University of Toronto Toronto Ontario Canada M5S 1A4 Abstract Ambiguities related to intension and their consequent inference failures are a diverse group both syntactically and semantically. One particular kind of ambiguity that has received little attention so far is whether it is the speaker or the third party to whom a description in an opaque third-party attitude report should be attributed. The different readings lead to different inferences in a system modeling the beliefs of external agents. We propose that a unified approach to the representation of the alternative readings of intension-related ambiguities can be based on the notion of a descriptor that is evaluated with respect to intensionality the beliefs of agents and a time of application. We describe such a representation built on a standard modal logic and show how it may be used in conjunction with a knowledge base of background assumptions to license restricted substitution of equals in opaque contexts. 1. Introduction Certain problems of ambiguity and inference failure in opaque contexts are well known opaque contexts being those in which an expression can denote its intension or underlying concept rather than any particular extension or instance. For example 1 admits two readings 1 Nadia is advertising for a penguin with whom she could have a long-term meaningful relationship. On the transparent or extensional or de re reading there is some particular penguin that Nadia is after 2 Nadia is advertising for a penguin with whom she could have a long-term meaningful relationship whom she met at a singles bar last week and fell madly in love with but lost the phone number of. On the opaque or intensional or de dictò reading Nadia wants any entity that meets her criteria 3 Nadia is advertising for any penguin with whom she could have a long-term meaningful .