Resumen Definimos un nuevo analizador para Gramáticas de Adjunción de Árboles (TAGs, Tree Adjoining Grammars) que es una extensión del analizador ascendente guiado por la esquina izquierda para Gramáticas Incontextuales (CFGs, Context Free Grammars). La complejidad temporal teórica del nuevo analizador permanece en la cota del análisis de TAGs, siendo ésta de O(n6) en el peor de los casos, dond...

The paper describes a system that can automatically generate tree adjoining grammars from abstract specifications. Our system is based on the use of tree descriptions to specify a grammar by separately defining pieces of tree structure that encode independent syntactic principles. Various individual specifications are then combined to form the elementary trees of the grammar. The system enables...

This paper describes the use of verb class memberships as a means of capturing generalizations about manner-of-motion verbs in Synchronous Tree Adjoining Grammars, STAGs, [20, 21, 22]. This approach allows STAGs, which are essentially transfer-based, to take advantage of the same types of generalizations which are generally thought of as wholly the domain of interlingua systems without giving u...

Starting from the model proposed by means of Grammatical Evolution, we extended the applicability of the parallel and cooperative searching processes of Evolutionary Algorithms to a new topic, Tree Adjoining Grammars parsing. We evolved derived trees using a string-tree-representation. We also could use a linear matching function to compare the yield of a derived tree with a given input and the...

In this paper we show that non-context-free phenomena can be captured using only limited logical means. In particular, we show how to encode a Tree Adjoining Grammar [16] into a weakly equivalent monadic context-free tree grammar (MCFTG). By viewing MCFTG-rules as terms in a free Lawvere theory, we can translate a given MCFTG into a regular tree grammar. The latter is characterizable by both a ...

In this paper we present a chart-based head corner parsing algorithm for Tree Adjoining Grammars (TAGs). We then present an improved algorithm that has a O(n) bound for the number of head-corner predictions as compared to previous approaches which have a bound of O(n). The improvement is made possible by changing the de nition of headcorner traversal and moving some aspects of top-down predicti...

Tree Adjoining Grammar (TAG) is a formalism that has become very popular for the description of natural languages. However, the parsers for TAG that have been defined on the basis of the Earley’s algorithm entail important computational costs. In this article, we propose to extend the left corner relation from Context Free Grammar (CFG) to TAG in order to define an efficient left corner parser ...

This paper shows how DATR, a widely used formal language for lexical knowledge representation, can be used to define an LTAG lexicon as an inheritance hierarchy with internal lexical rules. A bottom-up featural encoding is used for LTAG trees and this allows lexical rules to be implemented as covariation constraints within feature structures. Such an approach eliminates the considerable redunda...

We present the implementation of a system which extracts not only lexicalized grammars but also feature-based lexicalized grammars from Korean Sejong Treebank. We report on some practical experiments where we extract TAG grammars and tree schemata. Above all, full-scale syntactic tags and well-formed morphological analysis in Sejong Treebank allow us to extract syntactic features. In addition, ...

Overview The CRISP domain is motivated by the problem of sentence generation in natural language generation (NLG).1 NLG is a major subfield of natural language processing, concerned with computing natural language sentences or texts that convey a given piece of information to an audience. In the sentence generation task, we focus on generating a single sentence that expresses a given meaning ac...