## Reflections on [Boffa 1988] Consis(NFU) proof

### Sergei Tupailo

Thursday, 4 May 2006, 14:00

Cybernetica Bldg (Akadeemia tee 21), room B101

**Abstract**: We analyse the proof in question and study
possibilities of extending it to a proof of Consis(NF).

Consistency of New Foundations (NF), relative to (any extension of)
Zermelo-Fraenkel set theory, is one of the oldest and very important
open problems in Mathematical Logic / Set Theory: next year it will
turn 70. (This is only slightly younger than Mathematical Logic
itself.) New Foundations is a set theory built on a different
principle than theories of Zermelo-Fraenkel family. Many subsystems of
NF are known to be consistent.

First reference:

M. Boffa. ZFJ and the consistency problem for NF. Jahrbuch der Kurt
Gödel Gesellschaft (Wien), pp. 102--106, 1988.

P.S. I will also report on the Gödel Centenary Symposium,
which was held in Vienna, April 27-29.

Tarmo Uustalu

Last update 3.5.2006