Hi, please note that the following technical report is available on http://aib.informatik.rwth-aachen.de: Achim Blumensath: Axiomatising Tree-interpretable Structures 2001-10 Abstract: We introduce the class of tree-interpretable structures which generalises the notion of a prefix-recognisable graph to arbitrary relational structures. We prove that every tree-interpretable structure is finitely axiomatisable in guarded second-order logic with cardinality quantifiers. Note: This is an extended version of the corresponding STACS'02 paper. Best regards, Martin Leucker -- ----------------------------------------------------------------------- | Martin Leucker | Address: | | Department of Computer Science | Lehrstuhl fuer Informatik II | | University of Technology Aachen | Ahornstr. 55 | | Germany | D-52056 Aachen | ----------------------------------------------------------------------- | Tel.: (office) +49/(0)241/80-21210 (private) +49/(0)241/877073 | | Email: leucker@informatik.rwth-aachen.de Fax: +49/(0)241/80-22217 | | Web: http://www-i2.informatik.rwth-aachen.de/leucker/ | -----------------------------------------------------------------------