Two-part and k-Sperner families: New proofs using permutations. Siam Journal on Discrete Mathematics. 2005;19(2):489-500. Abstract
Two-part and k-Sperner families: New proofs using permutations
This is a paper about the beauty of the permutation method. New and shorter proofs are given for the theorem [ P. L. Erd. os and G. O. H. Katona, J. Combin. Theory. Ser. A, 43 ( 1986), pp. 58 – 69; S. Shahriari, Discrete Math., 162 ( 1996), pp. 229 – 238] determining all extremal two-part Sperner families and for the uniqueness of k-Sperner families of maximum size [ P. Erd. os, Bull. Amer. Math. Soc., 51 ( 1945), pp. 898 – 902].
Convex Hulls Of More-Part Sperner Families. Graphs and Combinatorics. 1986;2(2):123-34.
All Maximum 2-Part Sperner Families. Journal of Combinatorial Theory Series A. 1986;43(1):58-69.
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