Venn diagrams
Nov. 26th, 2010 10:21 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
eubSo apparently a Venn diagram is not what I always thought. What I always thought was a Venn diagram -- represent set relations as regions in the plane -- is an Euler diagram. A Venn diagram is specifically an Euler diagram that represents all of the combinations of set membership.
Crazy theorem: there exists a rotationally symmetric Venn diagram of order n if and only if n is prime. The "if" is a 2004 result; the "only if" is easier but not so easy.
Pretty pictures of Venn diagrams:
Crazy theorem: there exists a rotationally symmetric Venn diagram of order n if and only if n is prime. The "if" is a 2004 result; the "only if" is easier but not so easy.
Pretty pictures of Venn diagrams:
