João Enes
CMAFCIO, Universidade de Lisboa

Abstract: In this talk we will present the standard ordinal notation system for ordinals less than $\varepsilon_0$. We will introduce the Veblen hierarchy of functions based on the class of additively indecomposable ordinals. This will allow us to go beyond $\varepsilon_0$ and present a notation system for ordinals less than the Feferman-Schütte ordinal $\Gamma_0$.

This seminar is supported by National Funding from FCT - Fundação para a Ciência e a Tecnologia, under the project: UID/MAT/04561/2013.