A Genealogy of Phrase Structure

In standard approaches to NLP phrase structure is usually specified by a grammar. The coverage of such a grammar, especially in the case of performance data, is often insufficient; the grammar is subject to frequent modifications and this can bring about maintainability prob­ lems. In this paper we describe a relational basis underlying phrase structure. Based on that, a model is defined th a t yields hierarchical structure as the result of more abstract principles related to the combi­ natorial properties of linguistic units. The model is simple in use and easy to maintain, and provides an im portant key to the description of non-phrase structure configurations th a t require greater flexibility.