# Sh:E71

• Shelah, S. ECM presentation: Classifying classes of structures in model theory. Preprint.
• Abstract:
These are based on slides of the plenary talk of the ECM. We shall try to explain a new and surprising result that strongly indicates that there is more to be discovered about so-called dependent theories; and we introduce some basic definitions, results and themes of model theory required to explain it. In particular we present first order theories and their classes of models, so-called elementary classes. Among them we look for dividing lines, that is we try to classify them. It is not a priori clear but it turn out that there are good, interesting dividing lines, ones for which which there is much to be said on both sides of the divide. In this frame we explain about two notable ones: stable classes and dependent ones.
• Version 2021-04-18 (12p)
Bib entry
@unpublished{Sh:E71,
author = {Shelah, Saharon},
title = {{ECM presentation: Classifying  classes of structures in model theory}}
}