Retrieval from hierarchical texts by partial patterns

Abstract

Structured texts (for example dictionaries and user manuals) typically have a hierarchical (tree-like) structure. We describe a query language for retrieving information from collections of hierarchical text. The language is based on a tree pattern matching notion called tree inclusion. Tree inclusion allows easy expression of queries that use the structure and the content of the document. In using it a user need not be aware of the whole structure of the database. Thus a language based on tree inclusion is data independent, a property made necessary because of the great variance in the structure of the texts.