Mixed Parsing of Tree Insertion and Tree Adjoining Grammars (original) (raw)

PARSING TREE ADJOINING GRAMMARS AND TREE INSERTION GRAMMARS WITH SIMULTANEOUS ADJUNCTIONS

A large part of wide coverage Tree Adjoining Grammars (TAG) is formed by trees that satisfy the restrictions imposed by Tree Insertion Grammars (TIG). This characteristic can be used to reduce the practical complexity of TAG parsing, applying the standard adjunction operation only in those cases in which the simpler cubic-time TIG adjunction cannot be applied. In this paper, we describe a parsing algorithm managing simultaneous adjunctions in TAG and TIG.

Variants of mixed parsing of TAG and TIG

Traitement Automatique des Langues, 2003

Tree Adjoining Grammar (TAG) is a useful formalism for describing the syntactic structure of natural languages. In practice, a large part of wide coverage TAGs is formed by trees that satisfy the restrictions imposed by Tree Insertion Grammar (TIG), a simpler formalism. This characteristic can be used to reduce the practical complexity of TAG parsing, applying the standard adjunction operation only in those cases in which the simpler cubic-time TIG adjunction cannot be applied. A major obstacle to this task is posed by the fact that simultaneous adjunctions are forbidden in TAG but they are allowed in TIG. In this article, we describe several algorithms for mixed parsing of TAG and TIG: a first one forbidding simultaneous adjunctions, a second one allowing this kind of adjunctions, and a third one which extends the second one to preserve the correct prefix property.

Bidirectional Parsing Of Lexicalized Tree Adjoining Grammars

1991

In this paper a bidirectional parser for Lexicalized Tree Adjoining Grammars will be presented. The algorithm takes advantage of a peculiar characteristic of Lexicalized TAGs, i.e. that each elementary tree is associated with a lexical item, called its anchor. The algorithm employs a mixed strategy: it works bottom-up from the lexical anchors and then expands (partial) analyses making top-down predictions. Even if such an algorithm does not improve tim worst-case time bounds of already known TAGs parsing methods, it could be relevant from the perspective of linguistic information processing, because it employs lexical information in a more direct way. -27 -Procedure 3 Move-dot-left Input A slate s=[

Multiple Adjunction in Feature-Based Tree-Adjoining Grammar

Computational Linguistics, 2015

In parsing with Tree Adjoining Grammar (TAG), independent derivations have been shown by Schabes and Shieber (1994) to be essential for correctly supporting syntactic analysis, semantic interpretation, and statistical language modeling. However, the parsing algorithm they propose is not directly applicable to Feature-Based TAGs (FB-TAG). We provide a recognition algorithm for FB-TAG that supports both dependent and independent derivations. The resulting algorithm combines the benefits of independent derivations with those of Feature-Based grammars. In particular, we show that it accounts for a range of interactions between dependent vs. independent derivation on the one hand, and syntactic constraints, linear ordering, and scopal vs. nonscopal semantic dependencies on the other hand.

A Lexicalized Tree Adjoining Grammar for English

1990

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 so...

Multi-Component Tree Insertion Grammars

Formal Grammar, 2011

In this paper we introduce a new mildly context sensitive formalism called Multi-Component Tree Insertion Grammar. This formalism is a generalization of Tree Insertion Grammars in the same sense that Multi-Component Tree Adjoining Grammars is a generalization of Tree Adjoining Grammars. We show that this class of grammatical formalisms is equivalent to Multi-Component Tree Adjoining Grammars, and that it also defines a hierarchy of languages whose supplementary formal power between two increasing levels is more gently delivered than the one given by Multi-Component Tree Adjoining Grammars. We suspect that this increase of accuracy may be used to find the right amount of formal power needed for such and such linguistic description. We show that Multi-Component Tree Insertion Grammars and simple Range Concatenation Grammars are equivalent and we show how to transform a grammar of one type into an equivalent grammar of the other type. Such a transformation gives a method to build efficient parsers for Multi-Component Tree Insertion Languages.

Fast LR parsing using rich (Tree Adjoining) Grammars

Proceedings of the ACL-02 conference on Empirical methods in natural language processing - EMNLP '02, 2002

We describe an LR parser of parts-ofspeech (and punctuation labels) for Tree Adjoining Grammars (TAGs), that solves table conflicts in a greedy way, with limited amount of backtracking. We evaluate the parser using the Penn Treebank showing that the method yield very fast parsers with at least reasonable accuracy, confirming the intuition that LR parsing benefits from the use of rich grammars. 1 Unlike (Wright and Wrigley, 1991)'s approach who tries to transpose PCFG probabilities to LR tables, facing difficulties which, to the best of our knowledge, have not been yet solved to content (cf. also (Ng and Tomita, 1991; Wright et al., 1991; Abney et al., 1999)).

Augmenting the automated extracted tree adjoining grammars by semantic representation

Proceedings of the 6th International Conference on Natural Language Processing and Knowledge Engineering(NLPKE-2010), 2010

MICA [I] is a fast and accurate dependency parser for English that uses an automatically L TAG derived from Penn Treebank (PTB) using the Chen's approach [7]. However, there is no semantic representation related to its grammar. On the other hand, XTAG [20] grammar is a hand crafted LTAG that its elementary trees were enriched with the semantic representation by experts. The linguistic knowledge embedded in the XT AG grammar caused it to being used in wide variety of natural language applications. However, the current XTAG parser is not as fast and accurate as well as the MICA parser.