# Venn diagram

## English

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A 3-set Venn diagram, which is split by contours into 8 simply connected regions.

### Etymology

Named after John Venn (1834–1923), British mathematician and philosopher.

### Noun

Venn diagram (plural Venn diagrams)

1. (set theory) A diagram representing some sets by contours of closed shapes, such as circles or ellipses (and sometimes also the universal set as a rectangle enclosing all of these shapes), and indicating the relationships between the sets: by overlapping the shapes to show that the corresponding sets have a non-empty intersection, and by possibly (but not necessarily) enclosing all of the sets (which are proper subsets of the universal set) within a universal set (represented typically by a rectangle); such that the total number of simply connected regions is ${\displaystyle 2^{n}}$, where n is the number of depicted sets which are proper subsets of the universal set.