Please register and log-in to create and edit pages

User Tools

    Please register and log-in to create and edit pages

Site Tools

Main Menu

Main menu
Click categories to expand

A-Z listingplugin-autotooltip__plain plugin-autotooltip_bigA-Z listing

This is an alphabetical index of all content pages.

Other categories



Also see

Importance Ratings

Wikenigma supports:

Feeds etc
rss / xml feed
sitemap file
A-Z listing (archived)

Wikenigma - an Encyclopaedia of Unknowns Wikenigma - an Encyclopaedia of the Unknown Science

Four Color Theorem

Note: This theorem is widely regarded as having been solved. As of Apr. 2019, this entry is now moved to 'Deprecated'

The Four Color Theorem states that given any separation of a plane into contiguous regions, producing a figure called a map, no more than four colors are required to color the regions of the map so that no two adjacent regions have the same color. Source: Wikipedia

Computational tests, checking millions of possible configurations, have never found an exception. (note that a formal proof with 5 colors was made in the late 19th century by Percy Heawood, seeWikipedia ).

A 'machine generated proof' was described by Georges Gonthier of Microsoft Research Cambridge England, in 2007. See: Asian Symposium on Computer Mathematics, ASCM 2007 Asian Symposium on Computer Mathematics, ASCM 2007: Computer Mathematics pp 333-333

Also see Formal Proof—The Four Color Theorem

    Share this page :


Dear reader : Do you have any suggestions for the site's content?

Ideas for new topics, and suggested additions / corrections for old ones, are always welcome.

If you have skills or interests in a particular field, and have suggestions for Wikenigma, get in touch !

Or, if you'd like to become a regular contributor . . . request a login password. Registered users can edit the entire content of the site, and also create new pages.

( The 'Notes for contributors' section in the main menu has further information and guidelines etc.)

Show another (random) page