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...
We define tree automata with global constraints (TAGC), generalizing the well-known class of tree automata with global equality and disequality constraints [14] (TAGED). TAGC can...
We study visibly pushdown automata (VPA) models for expressing and evaluating queries, expressed using MSO formulas, on words with a nesting structure (like XML documents). We de...
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...