A logical framework for the temporal semantics and natural-language querying of historical databases
James Clifford · 1982
It is difficult to imagine a successful semantic theory in which time is not an integral component. In this dissertation we examine the connection between two areas of semantics, namely the semantics of databases and the semantics of natural language, and link them together through a common view of the semantics of time. Part One presents the thesis that an essential ingredient for the success of efforts to incorporate more real world semantics into database models is a coherent theory of the semantics of time. We define the historical database model (HDB) as a means of incorporating a temporal semantics within the relational and entity-relationship database models. The HDB model is a very general theory, one which ascribes only the simplest and most intuitive properties to time and defines a simple relationship between time and the other elements of the database model. Part Two presents a formally defined English database query language QE-III, whose semantic theory makes explicit reference to the notion of denotation with respect to a moment of time. This language is defined as a Montague Grammar with a somewhat simplified semantic theory; it offers a natural correspondence to the interpretation of queries in a database context. QE-III is provided with a formal syntax, semantics and pragmatics, each component designed with the database application in mind. This application has motivated several extensions to the traditional conception of a Montague Grammar, extensions that are interesting in their own right: the inclusion of a formal pragmatic component, the inclusion of time-denoting expressions and temporal operators, an analysis of verb meanings into primitive meaning units derived from the database schema, and the inclusion of certain forms of direct questions.