Symmetric Venn Diagram Construction
We show on the left a symmetric chain decomposition of
the "Necklace Poset" for n=5, that consists of the orbits of the
Boolean lattice for n=5 under rotation. Extra connections that
join the two chains are shown. We take a dual of this diagram
(viewing the left and right sides as separate regions), and
rotate the diagram round as indicated. The five copies yield the
symmetric Venn diagram for five sets shown on the right. (Shown
is my version of the method of Peter Hamburger.)
