Antichains in the set of subsets of a multiset
โ Scribed by G.F Clements
- Publisher
- Elsevier Science
- Year
- 1984
- Tongue
- English
- Weight
- 946 KB
- Volume
- 48
- Category
- Article
- ISSN
- 0012-365X
No coin nor oath required. For personal study only.
โฆ Synopsis
A set F of distinct subsets x of a finite muhiset M (that is, a set with several different kinds of elements) is a c-antichain if for no c+l elements Xo, xl ..... x c of F does XoCXlc...=xยข hold. The weight of F, wF, is the total number of elements of M in the various elements x of F. For given integers f and c, we find min wF, where the minimum is taken over all f-element c-antichains F. Daykin [9, has solved this problem for ordinary sets and Clements [3] has solved it for multisets, but only for c = 1.
๐ SIMILAR VOLUMES
A multiset M is a finite set consisting of several different kinds of elements, and an antichain F is a set of incomparable subsets of M. With P and \_F denoting respectively the set of subsets which contain an element of F or are contained in an element of F, we find the best upper bound for min(lF
We consider the random poset P(n, p) which is generated by first selecting each subset of [n]=[1, ..., n] with probability p and then ordering the selected subsets by inclusion. We give asymptotic estimates of the size of the maximum antichain for arbitrary p= p(n). In particular, we prove that if p
## Behrendt, G., The lattice of antichain cutsets of a partially ordered set, Discrete Mathematics 89 (1991) 201-202. Every finite lattice is isomorphic to the lattice of antichain cutsets of a finite partially ordered set whose chains have at most three elements. A subset A of a partially order