Non-empty cross-3-intersection theorems of subsets

  • Shiquan Wu
Session 6B: Combinatorics
Part of the Lecture Notes in Computer Science book series (LNCS, volume 959)


Maximum families of subsets satisfying some specified conditions are widely studied in combinatorics on set systems. In this paper, an extremal problem on subsets is considered. Let C n k denote the set of all k-subsets of an n- set. Assume AC n a and BC n b , (A B) is called a cross-t-intersecting family if ¦ A ∩ B ¦≥ t for any AA, BB. For t=3, maximum non-empty cross-3-intersecting families of a- and b- subsets are obtained.


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Copyright information

© Springer-Verlag Berlin Heidelberg 1995

Authors and Affiliations

  • Shiquan Wu
    • 1
  1. 1.System Engineering and Mathematics DepartmentNational University of Defense Technology ChangshaHunanChina

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