In the Venn diagram of where the region sits today, it is not difficult to see where the overlap lies.
1884, named for English logician John Venn (1834-1923) of Cambridge, who explained them in the book "Symbolic Logic" (1881).
A diagram that uses circles to represent sets, in which the relations between the sets are indicated by the arrangement of the circles. For example, drawing one circle within another indicates that the set represented by the first circle is a subset of the second set. The Venn diagram is named after its inventor, British mathematician John Venn (1834-1923).