To appear
Stefan Kiefer, Michael Luttenberger, and Javier Esparza. On the convergence of Newton's method for monotone systems of polynomial equations. In Proceedings of the 39th ACM Symposium on Theory of Computing (STOC), San Diego, California, USA, to appear.	GZipped PostScript (192 kB) PDF (183 kB) Info
Javier Esparza, Stefan Kiefer, and Michael Luttenberger. An extension of Newton's method to -continuous semirings. In Proceedings of the 11th International Conference on Developments in Language Theory (DLT), Lecture Notes in Computer Science, Turku, Finland, to appear.	GZipped PostScript (178 kB) PDF (167 kB) Info Tech report version
2007
Javier Esparza, Stefan Kiefer, and Michael Luttenberger. On fixed point equations over commutative semirings. In Wolfgang Thomas and Pascal Weil, editors, Proceedings of the 24th International Symposium on Theoretical Aspects of Computer Science (STACS), volume 4393 of Lecture Notes in Computer Science, pages 296–307, Aachen, Germany, 2007.	GZipped PostScript (179 kB) PDF (162 kB) Info Tech report version
2006
Javier Esparza, Stefan Kiefer, and Stefan Schwoon. Abstraction refinement with Craig interpolation and symbolic pushdown systems. In Holger Hermanns and Jens Palsberg, editors, Proceedings of the 12th International Conference on Tools and Algorithms for the Construction and Analysis of Systems (TACAS), volume 3920 of Lecture Notes in Computer Science, pages 489–503, Vienna, Austria, 2006.	GZipped PostScript (182 kB) PDF (174 kB) Info Tech report version
2005
Stefan Kiefer. Abstraction refinement for pushdown systems. Master's thesis, Universität Stuttgart, 2005.	GZipped PostScript (329 kB) PDF (557 kB) Info Slides
2003
Stefan Kiefer. Die Menge der virtuellen Verbindungen im Spiel Hex ist PSPACE-vollständig. Studienarbeit Nr. 1887, Universität Stuttgart, Juli 2003. In German.	GZipped PostScript (280 kB) PDF (375 kB) Info