Superantichains in the Lattice of Partitions of a Set
Sha Ji-chang, Daniel J. Kleitman · Studies in Applied Mathematics · 1984
A construction of superantichains in the lattice of partitions of finite sets is presented that works for set sizes above 107. The construction refines Canfield's, which worked only for set sizes above 1020, and provides a classification of the properties of partitions which allow such antichains to exist.