Type-Logical Syntax

A novel logic-based framework for representing the syntax–semantics interface of natural language, applicable to a range of phenomena. In this book, Yusuke Kubota and Robert Levine propose a type-logical version of categorial grammar as a viable alternative model of natural language syntax and semantics. They show that this novel logic-based framework is applicable to a range of phenomena—especially in the domains of coordination and ellipsis—that have proven problematic for traditional approaches. The type-logical syntax the authors propose takes derivations of natural language sentences to be proofs in a particular kind of logic governing the way words and phrases are combined. This logic builds on and unifies two deductive systems from the tradition of categorial grammar; the resulting system, Hybrid Type-Logical Categorial Grammar (Hybrid TLCG) enables comprehensive approaches to coordination (gapping, dependent cluster coordination, and right-node raising) and ellipsis (VP ellipsis, pseudogapping, and extraction/ellipsis interaction). It captures a number of intricate patterns of interaction between scopal operators and seemingly incomplete constituents that are frequently found in these two empirical domains. Kubota and Levine show that the hybrid calculus underlying their framework incorporates key analytic ideas from competing approaches in the generative syntax literature to offer a unified and systematic treatment of data that have posed considerable difficulties for previous accounts. Their account demonstrates that logic is a powerful tool for analyzing the deeper principles underlying the syntax and semantics of natural language

Hybrid Type-Logical Grammars, First-Order Linear Logic and the Descriptive Inadequacy of Lambda Grammars

In this article we show that hybrid type-logical grammars are a fragment of first-order linear logic. This embedding result has several important consequences: it not only provides a simple new proof theory for the calculus, thereby clarifying the proof-theoretic foundations of hybrid type-logical grammars, but, since the translation is simple and direct, it also provides several new parsing strategies for hybrid type-logical grammars. Second, NP-completeness of hybrid type-logical grammars follows immediately. The main embedding result also sheds new light on problems with lambda grammars/abstract categorial grammars and shows lambda grammars/abstract categorial grammars suffer from problems of over-generation and from problems at the syntax-semantics interface unlike any other categorial grammar

Hypothetical-reasoning and radical non-constituent coordination in categorical logic

The paper investigates the connection between non-constituent coordination, as implemented in categorial grammar by means of a polymorphic type-assignment to lexical conjunctions, and hypothetical reasoning in Categorial Logics. A way of extending the logic is suggested, so that coordination can be applied to types depending on undischarged assumptions. By a certain ``resource manipulation'' of assumptions (of hypothetical reasoning), a late-discharge is facilitated, leading to what is referred to as the {em radical non-constituent coordination, wherby only basic types (and not functional types of any kind) are coordinated

A Labelled Analytic Theorem Proving Environment for Categorial Grammar

We present a system for the investigation of computational properties of categorial grammar parsing based on a labelled analytic tableaux theorem prover. This proof method allows us to take a modular approach, in which the basic grammar can be kept constant, while a range of categorial calculi can be captured by assigning different properties to the labelling algebra. The theorem proving strategy is particularly well suited to the treatment of categorial grammar, because it allows us to distribute the computational cost between the algorithm which deals with the grammatical types and the algebraic checker which constrains the derivation.Comment: 11 pages, LaTeX2e, uses examples.sty and a4wide.st

Multi-dimensional Type Theory: Rules, Categories, and Combinators for Syntax and Semantics

We investigate the possibility of modelling the syntax and semantics of natural language by constraints, or rules, imposed by the multi-dimensional type theory Nabla. The only multiplicity we explicitly consider is two, namely one dimension for the syntax and one dimension for the semantics, but the general perspective is important. For example, issues of pragmatics could be handled as additional dimensions. One of the main problems addressed is the rather complicated repertoire of operations that exists besides the notion of categories in traditional Montague grammar. For the syntax we use a categorial grammar along the lines of Lambek. For the semantics we use so-called lexical and logical combinators inspired by work in natural logic. Nabla provides a concise interpretation and a sequent calculus as the basis for implementations.Comment: 20 page

Higher-order Linear Logic Programming of Categorial Deduction

We show how categorial deduction can be implemented in higher-order (linear) logic programming, thereby realising parsing as deduction for the associative and non-associative Lambek calculi. This provides a method of solution to the parsing problem of Lambek categorial grammar applicable to a variety of its extensions.Comment: 8 pages LaTeX, uses eaclap.sty, to appear EACL9