2003/01/20 by Millist W. Vincent, Jixue Liu, Vincent, Millist W. +1
Computer Science · #Advanced Database Systems and Queries #Databases (cs.DB) #Distributed systems and fault tolerance #FOS: Computer and information sciences #H.2.1 #Semantic Web and Ontologies #cs.DB
paper · pdf · doi:10.48550/arxiv.cs/0301017
arxiv created 2003/01/20 · openalex publication_date 2003/01/20 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
XML is of great importance in information storage and retrieval because of its recent emergence as a standard for data representation and interchange on the Internet. However XML provides little semantic content and as a result several papers have addressed the topic of how to improve the semantic expressiveness of XML. Among the most important of these approaches has been that of defining integrity constraints in XML. In a companion paper we defined strong functional dependencies in XML(XFDs). We also presented a set of axioms for reasoning about the implication of XFDs and showed that the axiom system is sound for arbitrary XFDs. In this paper we prove that the axioms are also complete for unary XFDs (XFDs with a single path on the l.h.s.). The second contribution of the paper is to prove that the implication problem for unary XFDs is decidable and to provide a linear time algorithm for it.