Im Rahmen des Instituskolloquims findet am<p>

Freitag, den 27. Januar 2006 um 16.00 s.t.  in SR 9<p>

der Vortrag<br>
"Node Selection Queries in XML documents by Tree Automata"
<p>
von<br><center>
                Herrn Dr. Joachim Niehren<br>
           (INRIA Futurs, LIFL, Lille, France)</center>
<br>
statt<p>

Abstract<p>

Motivated by an application in Web information extraction,
we investigate n-ary node selection queries in HTML or XML
trees. In the first part, we discuss the application and present the SQUIRREL system that we developed during the last
2 years in Lille. In the second part, we turn to the formal foundations, which belong to the domain of database theory, logic and automata. We study n-ary node selection queries in trees that are represented by successful runs of tree automata. We show that run-based n-ary queries capture MSO, contribute algorithms for enumerating answers of n-ary queries, and study the complexity of the problem. We investigate the subclass of run-based n-ary queries by unambiguous tree automata.

Es laedt ein: Prof. Dr. Manfred Schmidt-Schau&szlig;