Friday, March 21, 201412:30 pmModel theory seminarGC 6417

The consistency of Peano Arithmetic

Henry Towsner

University of Pennsylvania

Henry Towsner

In 1936, only a few years after the incompleteness theorems were proved, Gentzen proved the consistency of Peano arithmetic by using transfinite induction up to the ordinal epsilon_0. I will give a short proof of the result, based on on the simplification introduced by Schutte, and discuss some of the consequences.