We are pleased to announce that on May 17, 2007 an international group of Set Theorists will come together in Bonn for a small meeting. The talks will be part of the "Oberseminar Mathematische Logik" and are partially supported by the Bonner Internationale Graduiertenschule (BIGS-Mathematics).
Any interested logicians are cordially invited to come to these talks. The talks will take place in the Hausdorff-Raum of the Math Department (Beringstraße 3).
The speakers are J. Alama (Stanford), P. Koepke (Bonn), B. Seyfferth (Bonn), S. Tupailo (Tallinn), J. Zapletal (University of Florida). B. Semmes' (Amsterdam) talk had to cancelled due to illness.
|Schedule - Thursday, May 17|
Ramsey capacities and forcing
Almost Ramsey cardinals
NF and indiscernibles in ZF
Doing alpha-recursion theory with ordinal machines
Euler's Polyhedron Formula à la MIZAR
Jesse Alama: Euler's Polyhedron Formula à la MIZAR
I report on recent progress toward a computer-checked formal proof of Euler's polyhedron formula, which has just now been formalized in the MIZAR system. I will talk about the formalization in detail, its fidelity to the informal proof that it follows (namely, chapter two of Imre Lakatos's "Proofs and Refutations", which again is based on Poincaré's novel approach to Euler's formula), and, finally, the prospects for improving the formalization (and the MIZAR system itself).
Segei Tupailo: NF and indiscernibles in ZF
We show how NF (Quine's "New Foundations") can be seen as a special (inner) model of ZF. First, we give a sufficient condition for [the famous long-standing open problem of] NF consistency. Next, in the ZF language, we will present a much simplified Specker's refutation of AC in NF (= in that model of ZF).
Jindra Zapletal: Ramsey capacities and forcing
I will state basic definitions and theorems of capacity theory and their basic connections with forcing. I will define the classes of strongly subadditive and Ramsey capacities and show how they are relevant in measure theoretic and forcing sense.