Antichain

Let be a finite Partially Ordered Set. An antichain in is a set of pairwise incomparable elements (e.g., a familyof Subsets such that, for any two of them, neither is a Subset of the other). TheWidth of is the maximum Cardinality of an Antichain in . For aPartial Order, the size of the longest Antichain is called the Width.

References

Sloane, N. J. A. SequenceA006826/M2469in ``An On-Line Version of the Encyclopedia of Integer Sequences.''http://www.research.att.com/~njas/sequences/eisonline.html and Sloane, N. J. A. and Plouffe, S.The Encyclopedia of Integer Sequences. San Diego: Academic Press, 1995.

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