Preserving Semantic Dependencies in Synchronous Tree Adjoining Grammar

al., 1995) point out the differences between TAG derivation structures and semantic or predicate- argument dependencies, and Joshi and VijayShanker (Joshi and Vijay-Shanker, 1999) de- scribe a monotonic compositional semantics based on attachment order that represents the desired dependencies of a derivation without underspecifying predicate-argument relationships at any stage. In this paper, we apply the Joshi and Vijay-Shanker conception of compositional semantics to the problem of preserving semantic dependencies in Synchronous TAG translation (Shieber and Schabes, 1990; Abeill6 et al., 1990). In particular, we describe an algorithm to obtain the semantic dependencies on a TAG parse forest and construct a target derivation forest with isomorphic or locally non-isomorphic dependencies in O(n 7) time