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Combinatorica

, Volume 13, Issue 3, pp 241–247 | Cite as

A generalization of the AZ identity

  • Rudolf Ahlswede
  • Ning Cai
Article

Abstract

The identity discovered in [1] can be viewed as a sharpening of the LYM inequality ([3], [4], [5]). It was extended in [2] so that it covers also Bollobás' inequality [6]. Here we present a further generalization and demonstrate that it shares with its predecessors the usefullness for uniqueness proofs in extremal set theory.

AMS subject classification code (1991)

05 A 19 04 A 20 

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Copyright information

© Springer-Verlag 1993

Authors and Affiliations

  • Rudolf Ahlswede
    • 1
  • Ning Cai
    • 1
  1. 1.Fakultät für MathematikUniversität BielefeldBielefeld 1Germany

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