So, instead, mathematicians hunt for symmetrical diagrams, which are easier to understand and are proven to exist only for Venn diagrams with a prime number of sets. For purity’s sake ...

A Venn diagram is a way of grouping different items. These groups are known as sets. We have a set of golf clubs or a set of dishes – these are just groups of those items. We write a set using a ...

Image: Wikimedia Commons) Things get prettier as the number of sets increases: Grünbaum and Edwards independently discovered this symmetrical Venn diagram for seven sets, the next prime number.