Editing Category:Venn diagrams

*These are comics that relate to {{w|Venn diagram}}s.  
**They should not be confused with [[:Category:Euler diagrams|Euler diagrams]] although some of the comic that mention Venn diagrams actually shows Euler diagrams instead.
**If Venn diagrams are mentioned, even though it is an Euler diagram, not a Venn diagram, then they will still be included here.
*[[Randall]] seems to have made mistakes, or maybe done this on purpose as indicated with the comic [[2721: Euler Diagrams]].
**Apart from that comic where he mentions that he wishes to call all Euler diagrams for Venn diagrams he has also made the "mistake" two time before:
***[[1180: Virus Venn Diagram]]
***[[2090: Feathered Dinosaur Venn Diagram]]
***All three are now included in both categories, as Venn diagrams are mentioned even though they are not drawn!
**A Venn diagram shows all possible combinations of two or more sets, including those with no elements, and therefore all of the circles must intersect. 
**An Euler diagram need only depict the non-empty combinations, and therefore does not have this constraint.
***All Venn diagrams are also Euler diagrams, but not the other way around! 
***Thus this category is a sub category of Euler diagrams. 
***Only the three mistake comics should be included directly in both categories. 
*In a Venn diagram every possible intersection must be shown. 
**In general for an n component Venn diagram there are 2<sup>n</sup> hypothetically possible zones, corresponding to some combination of inclusion or exclusion in each of the component sets. 
**A Venn diagram with 2 circles, see [[668: Pandora]], has 2<sup>2</sup> = 4 zones; one overlap zone, two zones without overlap and one outside zone.
**[[2122: Size Venn Diagram]] is the first comic to include five components, previously only Venn diagrams with two or three circles have been used in xkcd.

[[Category:Charts]]
[[Category:Euler diagrams]]