I was sent this by a friend, but the source is Cool Infographics, a valuable site. Colin Harman designed it, and it is a delight. Pass it on to friends and family, those who are most likely to remind you of this most frustrating triad.
A Venn diagram, according to Wikipedia, “shows all possible logical relations between a finite collection of sets… Venn diagrams were conceived around 1880 by John Venn (1834–1923), a British logician and philosopher. He is famous for introducing the Venn diagram, which is used in many fields including set theory, logic, and computer science.”
This is a Venn diagram by Rich Stevens 3, a former student of mine.
And this is a basic Venn diagram showing the intersection of two sets.