Syntactic Computation as Labelled Deduction: WH a case study

This paper addresses the question "Why do WH phenomena occur with the particular cluster of properties observed across languages -- long-distance dependencies, WH-in situ, partial movement constructions, reconstruction, crossover etc." These phenomena have been analysed by invoking a number of discrete principles and categories, but have so far resisted a unified treatment. The explanation proposed is set within a model of natural language understanding in context, where the task of understanding is taken to be the incremental building of a structure over which the semantic content is defined. The formal model is a composite of a labelled type-deduction system, a modal tree logic, and a set of rules for describing the process of interpreting the string as a set of transition states. A dynamic concept of syntax results, in which in addition to an output structure associated with each string (analogous to the level of LF), there is in addition an explicit meta-level description of the process whereby this incremental process takes place. This paper argues that WH-related phenomena can be unified by adopting this dynamic perspective. The main focus of the paper is on WH-initial structures, WH in situ structures, partial movement phenomena, and crossover phenomena. In each case, an analysis is proposed which emerges from the general characterisatioan of WH structures without construction-specific stipulation.Articl

Indefinites as Epsilon Terms: A Labelled Deduction Account

This paper gives an account of indefinites as epsilon terms within a model of utterance processing as a task of labelled deduction, in which partially specified inputs are progressively resolved during the interpretation process. The formal tools used are labelled deduction (Gabbay), the epsilon calculus (Meyer-Viol 1995), and a tree-logic (LOFT - Blackburn & Meyer-Viol 1994) which characterises the structure as it is incrementally built. The system has been partly implemented in SWI-Prolog as part of a longer-term project and the model is a transition system which defines the steps which license movement from state to state.Articl

Relative clauses, left-periphery effects, and the dynamics of language processing

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Language Understanding: A Procedural Perspective

In this paper we introduce the data structures and process structure of an incremental parser which reflects the underspecified nature of the information encoded in the NL string. We show how this parser can deal with so called crossover phenomena in a way other systems cannot. The the parser is formulated within the LDS framework and constructs parse trees with the help of a modal logic for finite trees. Wh-expressions are interpreted as constituents with underspecified tree location. The dynamics of the parser is formulated in terms of transition system in which the transitions between the parser states are effected by deduction rules.Articl

Linguistics, Logic and Finite Trees

A modal logic is developed to deal with finite ordered binary trees as they are used in (computational) linguistics. A modal language is introduced with operators for the `mother of', `first daughter of' and `second daughter of' relations together with their transitive reflexive closures. The relevant class of tree models is defined and three linguistic applications of this language are discussed: context free grammars, command relations, and trees decorated with feature structures. An axiomatic proof system is given for which completeness is shown with respect to the class of finite ordered binary trees. A number of decidability results follow.Articl