Weak functional dependencies and inference rules for XML
Guohua Liu · Journal of Computer Applications · 2007
The problem of functional dependencies for Extensible Markup Language(XML) is the foundation of further research for XML database.In this paper,first,based on the definitions of Document Type Definition(DTD) and XML tree given by M.Arenas et al.,concepts of null value,incomplete tree tuple,data value partial order and minimal extended tree were proposed.Second,the definition of weak functional dependency and its satisfaction were given.Then the problem of logical implication for weak functional dependencies was studied,and a set of inference rules for XML were presented.Finally,the correctness and completeness of the set were proved.