This paper describes an integrated generation system (INLGS) based on the formalism of Schema–Tree Adjoining Grammars with Unification (SU–TAGs). According to this system architecture, all knowledge bases are specified in the same formalism and run the same processing algorithm. A main advantage is that negotiation between generation components can easily be imposed on the system. Moreover, onl...

In the line of research extending statistical parsing to more expressive grammar formalisms, we demonstrate for the first time the use of tree-adjoining grammars (TAG). We present a Bayesian nonparametric model for estimating a probabilistic TAG from a parsed corpus, along with novel block sampling methods and approximation transformations for TAG that allow efficient parsing. Our work shows pe...

In this paper, I will develop the formal foundations of a theory of complexity that underlies theory of grammatical induction. The initial concern will be the learning theoretic foundations of linguistic locality. That is, I will develop a theory that will place bounds on the amount a learner can draw from an input text. These bounds will limit the amount of variation that could potentially be ...

This paper shows how DATR, a widely used formal language for lexical knowledge representation , can be used to define an I_TAG lexicon as an inheritance hierarchy with internal lexical rules. A bottom-up featu-ral 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 redu...

In this paper we show that an account for coordination can be constructed using the derivation structures in a lexicalized Tree Adjoining Grammar (LTAG). We present a notion of derivation in LTAGs that preserves the notion of fixed constituency in the LTAG lexicon while providing the flexibility needed for coordination phenomena. We also discuss the construction of a practical parser for LTAGs ...

We present an implementation of a chart-based head-corner parsing algorithm for lexicalized Tree Adjoining Grammars. We report on some practical experiments where we parse 2250 sentences from the Wall Street Journal using this parser. In these experiments the parser is run without any statistical pruning; it produces all valid parses for each sentence in the form of a shared derivation forest. ...

The parsing schemata formalism allows us to describe parsing algorithms in a simple, declarative way by capturing their fundamental semantics while abstracting low-level detail. In this work, we present a compilation technique allowing the automatic transformation of parsing schemata to efficient executable implementations of their corresponding algorithms. Our technique is general enough to be...

Take a finite set T of trees, and close it under the operation of substitution—replacing daughterless nonterminals by other trees in T whose root node label matches the nonterminal. The set of all terminal strings of trees in the resultant tree-set will be a context-free language (CFL), and for every CFL there will be such a finite set of trees that generates it under substitution. For an elega...

Language models for speech recognition typically use a probability model of the form Pr(anja1; a2; : : : ; an 1). Stochastic grammars, on the other hand, are typically used to assign structure to utterances. A language model of the above form is constructed from such grammars by computing the pre x probability P w2 Pr(a1 anw), where w represents all possible terminations of the pre x a1 an. The...