An approach to define flexible structural constraints in XQuery

This paper presents a formal definition of an extension of the XQuery Full-Text language: The proposed extension consists in adding two new flexible axes, named below and near, which express structural constraints that can be specified by the user. Both constraints are evaluated in an approximate way with respect to a considered path, and their evaluation produces a path relevance score for each retrieved element. The formal syntax and the semantics of the two new axis are presented and discussed.