Andrey O. Matveev, "A note on operators of deletion and contraction for antichains", International Journal of Mathematics and Mathematical Sciences, vol. 31, Article ID 603792, 5 pages, 2002. https://doi.org/10.1155/S0161171202108088
A note on operators of deletion and contraction for antichains
The operators of deletion and contraction for clutters are generalized to those for antichains of finite bounded posets. A generalization of the result by Seymour (1976), describing the relationship between the operators of deletion, contraction, and the blocker map, is considered as a comparison in the lattice of antichains of a poset.
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