k-Sperner family
= k-Sperner family
{c}
A $k$-Sperner family contains no inclusion chain of length $k+1$. Every <maximal chain in a Boolean lattice> therefore meets it in at most $k$ members, so its <Lubell mass> is at most $k$.
= k-Sperner family
{c}
A $k$-Sperner family contains no inclusion chain of length $k+1$. Every <maximal chain in a Boolean lattice> therefore meets it in at most $k$ members, so its <Lubell mass> is at most $k$.