Feature Unification in TAG Derivation Trees

TL;DR

This paper introduces feature-based regular tree grammars, a formalism that captures feature unification in TAG derivation trees, aiding in sentence semantics and generation.

Contribution

It presents a formalism and a translation method from feature-based TAGs to this new formalism, preserving derivation structures and unification.

Findings

Formalism captures feature unification in TAGs

Translation preserves original derivation structures

Facilitates sentence semantics analysis

Abstract

The derivation trees of a tree adjoining grammar provide a first insight into the sentence semantics, and are thus prime targets for generation systems. We define a formalism, feature-based regular tree grammars, and a translation from feature based tree adjoining grammars into this new formalism. The translation preserves the derivation structures of the original grammar, and accounts for feature unification.