Proof Society Seminar 08.06.2026 (at 13:00 UTC = 14:00 BST = 15:00 CEST)
Elaine Pimentel
The next Proof Society Seminar will take place on Monday 08 June 2026 at 15:00 CEST. Our speaker will be Andreas Weiermann, University of Ghent. Details can be found below.
Speaker: Andreas Weiermann, University of Ghent
Title: Logical limit laws and analytic combinatorics for the proof-theoretic ordinal of PA
Abstract: Given a sentence S from the first order (or monadic second order) language of linear orders one might ask what the probability is that S is true on the linear order determined by a randomly chosen ordinal below the proof-theoretic ordinal of PA. Here the notion of randomness is modeled in terms of asymptotic density or averaged asymptotic density. These densities are tied to counting questions for ordinals which are amenable to analytic combinatorics.
In this talk we will discuss some older results which have been obtained jointly with Alan Woods and we also cover a recent averaged zero one law emerging from the standard Gödel coding which is based on prime factorization and coding subterms at exponential positions. To prove the more recent results we used modern AI tools to some extent.
The Proof Society Seminar features leading researchers in proof theory and related areas of logic. Talks are held online via Zoom, usually on Mondays, approximately once per month. They begin at 13:00 UTC and last up to 75 minutes, followed by questions.
To find out how to attend, please visit the page: