String generating hypergraph grammars with word order restrictions

Abstract

Discontinuous constituents and free word order pose constant problems in natural language parsing. String generating hypergraph grammars have been proven useful for handling discontinuous constituents. In this paper we describe a new notation for hypergraph productions that allows on-the-fly interconnection of graph parts with regard to user-defined constraints. These constraints handle the order of nodes within the string hypergraph. The HyperEarley parser for string generating hypergraph grammars [1] is adapted to the new formalism. A German example is used for the explanation of the new notation and algorithms. © Springer-Verlag Berlin Heidelberg 2006.