Simple Euler Diagram

Relationships of sets A and B. Both have some but not all elements in common.

Leonhard Euler, an 18th century mathematician and predecessor of Venn, represented visually a variety of syllogistic arguments.

For an excellent reference on the use of these diagrams see the following Shin, Sun-Joo, Lemon, Oliver, "Diagrams", The Stanford Encyclopedia of Philosophy (Winter 2003 Edition) , Edward N. Zalta (ed.),