# Noon lecture

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On 21.09.2007 at 12:10 in S6, there is the following noon lecture:

# Large families of subsets avoiding a given configuration

## Jerrold R. Griggs

## University of South Carolina, Columbia, SC

## Abstract

Translating Tur\'an-type questions to ordered sets, we are interested in the maximum size La(n,H) of a family F of subsets of the set {1,2,...,n}, subject to the condition that a certain configuration (subposet H) is excluded.

For instance, Sperner's Theorem solves the problem for H being a two-element chain. We survey results of this kind, including bounds when H is the four-element N poset (joint with Gyula O.H. Katona) or a more general height two poset (joint with Linyuan Lincoln Lu).

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