Studies of Euler diagrams/foravo

This is the complement of the Boolean function that states the three arguments to be equal.

This function can be represented in one dimension closed to a circle. The corresponding graph is a hexagon.

In a 2 dimensions it can reasonably be be shown with two or no gapspots.
The latter means, that the three borders intersect in a single point.
This point could be enlarged into gapspot 0 or 7. (But that would be a random choice, which should be avoided.)

(Compare logota, the equivalent with 4 sets.)