The theory of saturated chain partitions of partial orders is applied to the minimum unichain covering problem in the product of partial orders (posets). Define the nested saturation property for a poset to be the existence of a sequence of chain partitions %,, %a, . . such that (e, is k-and k + l-s
Product partial orders with the sperner property
โ Scribed by Robert A. Proctor; Michael E. Saks; Dean G. Sturtevant
- Publisher
- Elsevier Science
- Year
- 1980
- Tongue
- English
- Weight
- 754 KB
- Volume
- 30
- Category
- Article
- ISSN
- 0012-365X
No coin nor oath required. For personal study only.
โฆ Synopsis
Sufficient conditions are established for the product of two ranked partially ordered sets to have the Sperner property. As a consequence, it is shown that the class of strongly Sperner rank-unimodal rank-symmetric partially ordered sets is closed under the operation of product. Counterexamples are given which preclude most small variations in the hypotheses or cnnclusions of the two main results.
๐ SIMILAR VOLUMES
If P and Q are partial orders, then the dimension of the cartesian product P x Q does not exceed the sum of the dimensions of P and Q. There are several known sufficient conditions for this bound to be attained, on the other hand, the only known lower bound for the dimension of a cartesian product i