Tree-adjoining grammar

About: Tree-adjoining grammar is a research topic. Over the lifetime, 2491 publications have been published within this topic receiving 57813 citations.

A Lexicalized Tree Adjoining Grammar for English

Abstract: This paper presents a sizable grammar for English written in the Tree Adjoining grammar (TAG) formalism. The grammar uses a TAG that is both lexicalized (Schabes, Abeille, Joshi 1988) and feature-based (VijayShankar, Joshi 1988). In this paper, we describe a wide range of phenomena that it covers. A Lexicalized TAG (LTAG) is organized around a lexicon, which associates sets of elementary trees (instead of just simple categories) with the lexical items. A Lexicalized TAG consists of a finite set of trees associated with lexical items, and operations (adjunction and substitution) for composing the trees. A lexical item is called the anchor of its corresponding tree and directly determines both the tree's structure and its syntactic features. In particular, the trees define the domain of locality over which constraints are specified and these constraints are local with respect to their anchor. In this paper, the basic tree structures of the English LTAG are described, along with some relevant features. The interaction between the morphological and the syntactic components of the lexicon is also explained. Next, the properties of the different tree structures are discussed. The use of S complements exclusively allows us to take full advantage of the treatment of unbounded dependencies originally presented in Joshi (1985) and Kroch and Joshi (1985). Structures for auxiliaries and raising-verbs which use adjunction trees are also discussed. We present a representation of prepositional complements that is based on extended elementary trees. This representation avoids the need for preposition incorporation in order to account for double whquestions (preposition stranding and pied-piping) and the pseudo-passive. A treatment of light verb constructions is also given, similar to what Abeille (1988c) has presented. Again, neither noun nor adjective incorporation is needed to handle double passives and to account for CNPC violations in these constructions. TAG'S extended domain of locality allows us to handle, within a single level of syntactic description, phenomena that in other frameworks require either dual analyses or reanalysis. In addition, following Abeille and Schabes (1989), we describe how to deal with semantic non compositionality in verb-particle combinations, light verb constructions and idioms, without losing the internal syntactic composition of these structures. The last sections discuss current work on PRO, case, anaphora and negation, and outline future work on copula constructions and small clauses, optional arguments, adverb movement and the nature of syntactic rules in a lexicalized framework. Comments University of Pennsylvania Department of Computer and Information Science Technical Report No. MSCIS-90-24. This technical report is available at ScholarlyCommons: http://repository.upenn.edu/cis_reports/527 A Lexicalized Tree Adjoining Grammar For English MS-CIS-90-24 LINC LAB 170 Anne Abeillh Kathleen Bishop Sharon Cote Yves Schabes Department of Computer and Information Science School of Engineering and Applied Science University of Pennsylvania Philadelphia, PA 19104-6389

Syntactic Pattern Recognition: An Introduction

Abstract: This book provides an introduction to basic concepts and techniques of syntactic pattern recognition. The presentation emphasizes fundamental and practical material rather than strictly theoretical topics, and numerous examples illustrate the principles. The subject is developed according to the following topics: introduction (background, patterns and pattern classes, approaches to pattern recognition, elements of a pattern recognition system, concluding remarks); elements of formal language theory (introduction; string grammars and languages; examples of pattern languages and grammars; equivalent context-free grammars; syntax-directed translations; deterministic, nondeterministic, and stochastic systems; concluding remarks); higher-dimensional grammars (introduction; tree grammars; web grammars; plex grammars; shape gammars; concluding remarks); recognition and translation of syntactic structures (introduction; string language recognizers; automata for simple syntax-directed translation; parsing in string languages; recognition of imperfect strings; tree automata; concluding remarks); stochastic grammars, languages, and recognizers (introduction; stochastic grammars and languages; consisting of stochastic context-free grammars; stochastic reocgnizers; stochastic syntax-directed translations; modified Cocke-Younger-Kasami parsing algorithm for stochastic errors of changed symbols; concluding remarks); and grammatical inference (introduction; inference of regular grammars; inference of context-free grammars; inference of tree grammars; inference of stochastic grammar; concluding remarks). 155 references, 93 figures, 4 tables. (RWR)

Hyperedge replacement graph grammars

Abstract: In this survey the concept of hyperedge replacement is presented as an elementary approach to graph and hypergraph generation. In particular, hyperedge replacement graph grammars are discussed as a (hyper)graph-grammatical counterpart to context-free string grammars. To cover a large part of the theory of hyperedge replacement, structural properties and decision problems, including the membership problem, are addressed.

Dependency systems and phrase-structure systems

Abstract: A language is considered here as a finite set of symbols (words of the language) together with a set of strings (finite sequences) of these symbols (sentences of the language). A grammar is a system of rules by means of which those strings which belong to the language (i.e., are sentences) are defined. Two types of grammars are dealt with-those based on dependency rules and those based on phrase-structure rules. Both of these supply the sentences that they analyze with additional structure; there is a very close relationship between these structures. Different notions of equivalence between grammars of the two types, based on structure similarities, are defined. Every dependency system has a “naturally corresponding≓ phrase-structure system but not vice versa. An effective necessary and sufficient condition for the existence of a “naturally corresponding≓ dependency system for a given phrase-structure system is given, and an effective way to construct it when it exists. Nevertheless, every set of strings defined by means of a grammar of one type is also defined by means of a grammar of the other type, which can be found effectively. However, the result above implies that there will be cases in which the second system will not be “naturally correlated≓ with the given one from a structural point of view.