A Symmetrical Beauty. A Non-simple \(7\)-Venn Diagram With A Minimum Vertex Set

Abstract

In this short note, using the method developed in [10] and [11], we construct a highly symmetrical, non-simple, attractive \(7\)-Venn diagram. This diagram has the minimum number of vertices, \(21\). The only similar two, published in [1] and [11], differ from ours in many ways. One of them was found by computer search [1]. Both of them are “necklace” type Venn diagrams (see [14] for definition), but ours is not.