Abstracting over Semantic Theories
Holt, Alexander G B
The topic of this thesis is abstraction over theories of formal semantics for natural language.It is motivated by the belief that a metatheoretical perspective can contribute both to a better theoretical understanding of semantic theories, and to improved practical mechanisms for developing theories of semantics and combining them with theories of syntax. The argument for a new way to understand semantic theories rest spartly on the present difficulty of accurately comparing and clasifying theories, aswell as on the desire to easily combine theories that concentrate on different areas of semantics. There is a strong case for encouraging more modularity in the structure of semantic theories, to promote a division of labour, and potentially the development of reusable semantic modules. A more abstract approach to the syntax-semantics interface holds out the hope of further benefits, notably a degree of guaranteed semantic coherence via typesor constraints. Two case studies of semantic abstraction are presented. First,alternative characterizations of intensional abstraction and predication are developed with respect to three different semantic theories, but in a theory-independent fashion. Second,an approach to semantic abstraction recently proposed by Johnson and Kayis analyzed in detail,and the nature of its abstraction described with formal specifications. Finaly, a programme for modular semantic specifications is described, and applied to the area of quantification and anaphora,demonstrating succesfuly that theory-independent devices can be used to simultaneously abstract across both semantic theories and syntax-semantics interfaces.