The partition lattice of order n is the lattice of setPartitions of the set {1,...,n} with ordering given by refinement. That is, the set-partition p is greater than or equal to the set-partition q if each part of p is contained in exactly one part of q.
i1 : partitionLattice 3 o1 = Relation Matrix: | 1 1 1 1 1 | | 0 1 0 0 1 | | 0 0 1 0 1 | | 0 0 0 1 1 | | 0 0 0 0 1 | o1 : Poset |