Topological Dependency Trees: A Constraint-based Account of Linear Precedence
Autor: Denys Duchier and Ralph Debusmann
Herausgeber:
Linear precedence in so-called free word order languages remains
challenging for modern grammar formalisms. To address this issue,
we describe a new framework for dependency grammar, with a modular
decomposition of immediate dependency and linear precedence. Our
approach distinguishes two orthogonal yet mutually constraining
structures: a syntactic dependency tree (ID tree) and a topological
dependency tree (LP tree). The ID tree is non-projective, and even
non-ordered, and
its edges are labeled by syntactic roles. The LP tree is
projective, partially ordered, and its edges are labeled by
topological fields. The shape of the LP tree is a
flattening of the ID tree's obtained by allowing nodes to `climb
up'. Our theory of ID/LP trees is formulated in terms of
(a) lexicalized constraints and (b) principles governing e.g. climbing
conditions. We illustrate it with a detailed account of word order
phenomena in the verbal complex of German verb final sentences.
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