Tree-adjoining grammars are a generalization of context-free grammars that are well suited to model human languages and are thus popular in computational linguistics. In the tree-adjoining grammar recognition problem, given a grammar Γ and a string s of length n, the task is to decide whether s can be obtained from Γ. Rajasekaran and Yooseph’s parser (JCSS’98) solves this problem in time O(n), ...

Tree transducer formalisms were developed in the formal language theory community as generalizations of finite-state transducers from strings to trees. Independently, synchronous tree-substitution and -adjoining grammars arose in the computational linguistics community as a means to augment strictly syntactic formalisms to provide for parallel semantics. We present the first synthesis of these ...

In the literature, Tree Adjoining Grammars (TAGs) are propagated to be adequate for natural language description-analysis as well as generation. In this paper we concentrate on the direction of analysis. Especially important for an implementation of that task is how efficiently this can be done, i.e., how readily the word problem can be solved for TAGs. Up to now, a parser with O(n 6) steps in ...

Adjunction is a powerful operation that makes Tree Adjoining Grammar (TAG) useful for describing the syntactic structure of natural languages. In practice, a large part of wide coverage grammars written following the TAG formalism is formed by trees that can be combined by means of the simpler kind of adjunction defined for Tree Insertion Grammar. In this paper, we describe a parsing algorithm ...

We present a class-based approach to building a verb lexicon that makes explicit the close association between syntax and semantics for Levin classes. We have used Lexicalized Tree Adjoining Grammars to capture the syntax associated with each verb class and have augmented the trees to include selectional restrictions. In addition, semantic predicates are associated with each tree, which allow f...

Lexicalized Tree Adjoining Grammars have proved useful for NLP. However, numerous redundancy problems face LTAGs developers, as highlighted by Vijay-Shanker and Schabes (92). We present and a tool that automatically generates the tree families of an LTAG. It starts from a compact hierarchical organization of syntactic descriptions that is linguistically motivated and carries out all the relevan...

Recent results have established that there is a family of languages that is exactly the class of languages generated by three independently developed grammar formalisms: Tree Adjoining Grammm~, Head Grammars, and Linear Indexed Grammars. In this paper we show that Combinatory Categorial Grammars also generates the same class of languages. We discuss the slruclm'al descriptions produced by Combi...

The task of designing parsing algorithms for tree adjoining grammars could be simplified by providing a separation between the description of the parsing strategy and the execution of the parser. This can be accomplished through the use of Bottom-up Embedded Push-Down Automata. Towards this aim, we provide a formal and consistent definition of this class of automata and, by removing the finite-...

In this paper we discuss the formal relationship between the classes of languages generated by Tree Adjoining Grammars and Head Grammars. In particular, we show tha t Head Languages are included in Tree Adjoining Languages and tha t Tree Adjoining Grammars are equivalent to a modification of Head Grammars called Modified Head Grammars. The inclusion of MHL in HL, and thus the equivalence of HG'...

The task of designing parsing algorithms for tree adjoining grammars could be simpliied by providing a separation between the description of the parsing strategy and the execution of the parser. This can be accomplished through the use of Bottom-up Embedded Push-Down Automata. Towards this aim, we provide a formal and consistent deeni-tion of this class of automata and, by removing the nite-sta...