Down-set
= Down-set
{wiki=Lower_set}
A down-set is a family $\mathcal D$ such that $A\in\mathcal D$ and $B\subseteq A$ imply $B\in\mathcal D$. It is the complement of an up-set within the same Boolean lattice.
= Down-set
{wiki=Lower_set}
A down-set is a family $\mathcal D$ such that $A\in\mathcal D$ and $B\subseteq A$ imply $B\in\mathcal D$. It is the complement of an up-set within the same Boolean lattice.