Venn studied and taught logic and probability theory at Cambridge University, where he developed his method of using diagrams to illustrate the branch of mathematics known as set theory.

Venn diagrams are used to sort sets of data. The probability of an event not happening uses the complement of the region on the Venn diagram. Count the number of elements in each region.

This app displays an intricate Venn diagram, containing various combinations of set intersections, unions and complements. Users can shade the area they choose by clicking on the diagram. Users can ...