@InProceedings{acl01,
  author =       {Denys Duchier and Ralph Debusmann},
  title =        {Topological Dependency Trees: A Constraint-based Account of Linear Precedence},
  booktitle =    {Proceedings of the ACL 2001 Conference},
  year =         2001,
  address =      {Toulouse/FRA},
  authorURLs =   {http://www.loria.fr/~duchier/ and http://www.ps.uni-sb.de/~rade/},
  abstract =     {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.},
  keywords =     {dependency grammar, German, verb cluster},
}