A schematic diagram used in logic theory to depict collections of sets and represent their relationships. The Venn diagrams on two and three sets are illustrated above. The order-two diagram (left) consists of two intersecting circles, producing a total of four regions, A, B, A intersection B, and ∅ (the empty set, represented by none of the regions occupied). Here, A intersection B denotes the intersection of sets A and B.

circle | flower of life | Haruki's theorem | intersection | lens | magic circles | Reuleaux triangle | seed of life