THE ELECTRONIC JOURNAL OF COMBINATORICS (ed. June 2005), DS #5.

Venn Diagram Survey
Monotone Symmetric Diagrams Without Using Necklaces


Some monotone symmetric Venn diagrams cannot be constructed sector-by-sector using necklaces. To the left is a 7-Venn diagram that does not have n vertices through which all curves pass, and thus it cannot be broken down into 7 sectors. It has the minimum number of vertices for monotone diagrams. The diagram is rigid, so it is not isomorphic to any diagram constructable out of sectors. This diagram is from [Wes].


THE ELECTRONIC JOURNAL OF COMBINATORICS (ed. June 2005), DS #5.