Two-variable logic on data trees and XML reasoning

d Abstract] Mikolaj Boja?nczyk Faculty of Mathematics, Informatics and Mechanics Warsaw University Poland Claire David LIAFA Universit?e Paris 7 France Anca Muscholl LIAFA Universit?e Paris 7 France Thomas Schwentick Lehrstuhl Informatik I Universit?at Dortmund Germany Luc Segoufin INRIA & Universit?e Paris 11 France Motivated by reasoning tasks in the context of XML languages, the satisfiability problem of logics on data trees is investigated. The nodes of a data tree have a label from a finite set and a data value from a possibly infinite set. It is shown that satisfiability for two-variable first-order logic is decidable if the tree structure can be accessed only through the child and the next sibling predicates and the access to data values is restricted to equality tests. From this main result decidability of satisfiability and containment for a dataaware fragment of XPath and of the implication problem for unary key and inclusion constraints is concluded. Categories and Subj...

• Type: Conference
• Year: 2006
• Where: PODS
• Authors: Mikolaj Bojanczyk, Claire David, Anca Muscholl, Thomas Schwentick, Luc Segoufin
• Keywords: Database, Keywords First-order Logic, PODS 2006, Satisfiability Problem, Two-variable First-order Logic