If the model of free-form queries, which has proved successful for HTML based search on the Web, is made available for Grid services, it will serve as a powerful tool for scientis...
Abstract. Tree-walking automata (TWAs) recently received new attention in the fields of formal languages and databases. Towards a better understanding of their expressiveness, we c...
In this work we investigate the satisfiability problem for the logic XPath( , , =), that includes all downward axes as well as equality and inequality tests. We address this probl...
We consider the navigational core of XPath, extended with two operators: the Kleene star for taking the transitive closure of path expressions, and a subtree relativisation operat...
We consider a fragment of XPath named `forward-XPath', which contains all descendant and rightwards sibling axes as well as data equality and inequality tests. The satisfiabi...