Nested Venn Diagrams
N. J. Radcliffe
Nesting is used to extend Venn Diagrams from their usual practical
limit of three or four sets to a form that readily handles five to
eight sets. Although devised independently, such nested diagrams can
be viewed as the application to Venn Diagrams of an idea proposed in
1896 by Lewis Carroll, in the context of his alternative set diagrams.
Such nesting is rarely if ever used today, but has genuine practical
value; ironically, it appears to be more useful in the context of the
familar Venn Diagram than when applied to Lewis Carroll's own, less
popular, diagrams.