diagrams

Clever Venn diagrams I wish I had in middle school.

And in case you are curious what the word, Venn refers to:

"Venn diagrams were conceived around 1880 by John Venn.  The use of these types ofdiagrams in formal logic, according to Ruskey and M. Weston, is "not an easy history to trace, but it is certain that the diagrams that are popularly associated with Venn, in fact, originated much earlier. They are rightly associated with Venn, however, because he comprehensively surveyed and formalized their usage, and was the first to generalize them". Venn diagrams are very similar to Euler diagrams, which were invented by Leonhard Euler (1708–1783) in the 18th century.^[6] M. E. Baron has noted that Leibniz (1646–1716) in the 17th century produced similar diagrams before Euler, but much of it was unpublished. She also observes even earlier Euler-like diagrams by Ramon Lull in the 13th Century.^[7]

Venn himself did not use the term "Venn diagram" but kept speaking of "Eulerian Circles".

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