tailieunhanh - Báo cáo khoa học: "On Reasoning with Ambiguities"

The paper adresses the problem of reasoning with ambiguities. Semantic representations are presented that leave scope relations between quantifiers a n d / o r other operators unspecified. Truth conditions are provided for these representations and different consequence relations are judged on the basis of intuitive correctness. Finally inference patterns are presented that operate directly on these underspecified structures, . do not rely on any translation into the set of their disambiguations. empt to systematically derive the consequence relation that holds for reasoning with ambiguities on the basis of an empirical discussion of intuitively valid arguments. . | On Reasoning with Ambiguities Uwe Reyle Institute for Computational Linguistics University of Stuttgart D-70174 Stuttgart Germany e-mail uwe@ Abstract The paper adresses the problem of reasoning with ambiguities. Semantic representations are presented that leave scope relations between quantifiers and or other operators unspecified. Truth conditions are provided for these representations and different consequence relations are judged on the basis of intuitive correctness. Finally inference patterns are presented that operate directly on these underspecified structures . do not rely on any translation into the set of their disambiguations. 1 Introduction Whenever we hear a sentence or read a text we build up mental representations in which some aspects of the meaning of the sentence or text are left underspecified. And if we accept what we have heard or read as true then we will use these underspecified representations as premisses for arguments. The challenge is therefore to equip underspecified semantic representations with well-defined truth conditions and to formulate inference patterns for these representations that follow the arguments that we judge as intuitively correct. Several proposals exist for the definition of the language but only very few authors have addressed the problem of defining a logic of ambiguous reasoning. 8 considers lexical ambiguities and investigates structural properties of a number of consequence relations based on an abstract notion of coherency. It is not clear however how this approach could be extended to other kinds of ambiguities especially quantifier scope ambiguities and ambiguities triggered by plural NPs. 1 7 and 6 deal with ambiguities of the latter kind. They give construction rules and define truth conditions according to which an underspecified representation of an ambiguous sentence is true if one of its disambiguations is. The problem of reasoning is adressed only in 5 and 7 . 5 s