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         Four Colour Theorem:     more detail
  1. Graphs, Colourings and the Four-Colour Theorem (Oxford Science Publications) by Robert A. Wilson, 2002-03-28
  2. ON EXTENDED CONGRUENCES CONNECTED WITH THE FOUR-COLOUR MAP THEOREM. by P. J. (SIGNED) HEAWOOD, 1929-01-01

41. Encyclopædia Britannica
Search Tips. Your search four colour theorem. Log In or Subscribe Now. Expand yoursearch on four colour theorem with these databases Journals and magazines.
http://search.britannica.com/search?query=Four Colour Theorem

42. GottaBounce.com : Science & Technology : Math
Rate it. four colour theorem A new proof of the four colour theoremby Ashay Dharwadker using group theory and Steiner systems. Added
http://www.gottabounce.com/directory/Science_&_Technology/Math/
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Question of the Week: Do you think the Olympics where a success?
Yes No Not Sure Last Week's Question: What is your favorite kind of pet? Birds Cats Dogs Fish Reptiles Other Home > Math Displaying: 1 - 16 of Eric Weisstein's World of Mathematics Huge encyclopedia with nearly all Math terms explained. Added: Jan-03-2000 Visits: Bookmark it Tell a Friend Rate it Four Colour Theorem A new proof of the four colour theorem by Ashay Dharwadker using group theory and Steiner systems. Added: Dec-30-2000 Visits: Bookmark it Tell a Friend Rate it Four Colour Theorem A new proof of the four colour theorem by Ashay Dharwadker using group theory and Steiner systems. Added: Dec-30-2000 Visits: Bookmark it Tell a Friend Rate it Frequently Asked Questions in Math Before posting a question in the sci.math newsgroup, you should first look for the answer in this FAQ. (It's hardly comprehensive, unsurprisingly, as math is such a vast subject.) Added: Jan-03-2000 Visits: Bookmark it Tell a Friend Rate it Knot a Braid of Links Your rough guide to mathematics on the web. A new site is added each week. Unsorted.

43. Menu Termes Mal Traduits Terminologie Syntaxe Globale
four colour theorem ) The theorem
http://ibm2.cicrp.jussieu.fr/bdej/ILTS/jklm/terme/4colour.html
menu termes mal traduits terminologie syntaxe globale ... analyse de la ponctuation TERME four colour map theorem (Or "four colour theorem") The theorem stating that if the plane is divided into connected regions which are to be coloured so that no two adjacent regions have the same colour (as when colouring countries on a map of the world), it is never necessary to use more than four colours. The proof, due to Appel and Haken, attained notoriety by using a computer to check tens of thousands of cases and is thus not humanly checkable, even in principle. Some thought that this brought the philosophical status of the proof into doubt. There are now rumours of a simpler proof, not requiring the use of a computer. Il y a maintenant des rumeurs d'une preuve plus simple, n'exigeant pas l'utilisation d'un ordinateur. See also chromatic number Voir aussi "nombre chromatique"

44. Www.math.niu.edu/~rusin/known-math/99/chromatic
edu , Jesus CidSueiro jesusc@cs.berkeley.edu writes James Wanless wrote Anybody know what the analogue to the four colour theorem is in 3-D
http://www.math.niu.edu/~rusin/known-math/99/chromatic
From: kramsay@aol.com (KRamsay) Subject: Re: Geometry question Date: 08 May 1999 19:19:55 GMT Newsgroups: sci.math Keywords: chromatic number of non-planar graphs In article , Jesus Cid-Sueiro , Jesus Cid-Sueiro

45. Untitled
The first written document treating the four colour theorem is a letter from Augustusde Morgan to Sir William Rowan Hamilton, dated on October 23, 1852.
http://venere.mat.uniroma1.it/~combinat/seminario/anno000102/absfritsch.html
The 150th Birthday of the Four Colour Problem - Theorem The first written document treating the Four Colour Theorem is a letter from Augustus de Morgan to Sir William Rowan Hamilton, dated on October 23, 1852. More than 120 years of interesting mathematical research were needed for the first solution by Kenneth Appel, Wolfgang Haken and John Koch. The aim of the lecture is to present some special points of the history of the problem and to give an idea how the computer aided proof works. The strange point is that the truth of the theorem is still dependent on the reliability of the involved computer programs.

46. Study Guide: Part 2.2.2
The first is the four colour theorem (that every map can be coloured in such a waythat no two adjacent countries have the same colour, using only four colours
http://www.maths.ox.ac.uk/teaching/study-guide/p2.2.2.html
Part 2
New Skills
Formulating Maths
Introduction

Implications

Dependence

Proof
Introduction

Counter examples
Constructing proofs

Understanding

Experimentation

Precision
... Maths Symbols Summary
To disprove a mathematical statement, you should provide a specific counter example. If asked to decide whether a given statement is true or false and if your insight does not immediately provide the answer, try to prove the statement; then use your experience of the difficulties encountered to try to construct a counter example; then use your experience of those difficulties to try again to prove the statement, etc. To gain experience in constructing counter examples, you should practise by taking standard theorems, omitting part of the hypothesis, and trying to find counter examples to the conclusions.
In real-life problems, you do not know the answer until you have solved the problem. Undergraduate mathematics is rather different, in that in many problems you are told the answer, and required only to find out why it is the answer. However, from time to time, you will be asked questions in which you are required to determine whether a given statement is true or false. In these cases, it is always implicit that you should justify your answer (there are no prizes for guessing correctly). This means that if the statement is true, then you have to prove it; if the statement is false, then you have to disprove it. We shall give you some ideas in the subsequent sections of this chapter how to go about proving things, but in this section we tell you how to disprove (false) statements.

47. Italy Hotel Club - Italy Hotel Club
Inspired by Guthrie ’s “four colour theorem”, Italy Hotel Club has focusedon Business, Culture, Relaxation and Holidays as the four main categories
http://www.italyhotelclub.com/en_ihc.htm
Home Italy Hotel Club our Hotels Alghero Arezzo Bologna Brindisi Caserta Chianciano Terme Costa del Cilento Florence Gabicce Mare Genova Lamporecchio La Spezia Massa Marittima Milan - Hotel Enterprise Milan - Hotel Windsor Milan - Hotel Marconi Montegrotto Terme Napoli Pisa Prato Rome - Hotel Baileys Rome - Hotel Gambrinus S. Margherita Sassuolo Sirmione Sorrento Venice - S. Marco Palace Venice - Royal San Marco Venice - Ai Pini Verona Castel d'Azzano
These hotels are spread throughout the country and reflect the beauties and special qualities of our Bel Paese.
We have highlighted these to complete your holiday and
a wonderful stay
Business Culture Relaxation
and Holidays as the four main categories (colours) of Italian tourism. Each hotel in the Group, therefore, is presented in one or more colours - just as Italy has a multitude of attractions and interesting things to see and do,so IHC hotels offer visitors a variety of possibilities.
Four Colour Theorem
Francis Guthrie -1852
Italy Hotel Club
Presentation
Free stays

benefits program
Corporate rates Corporate program ... Press releases

48. Diskret Matematik C - Projects
It was first produced by Petersen (although others had refered to it earlier) inconnection with attempts by Tait to prove the four colour theorem by proving a
http://www.fmi.mh.se/matematik/kurser/c_diskret_matte/projects.html
Diskret Matematik C: Projects
Suggested Topics
Hadamard matrices
Give a seminar where you present a selection of construction methods for Hadamard matrices. Try to find the smallest number n for which your construction methods do not give a Hadamard matrix.
Marshall Hall Jr. : Combinatorial Theory (Wiley 1986)
and on the www via
http://www.research.att.com/~njas/hadamard/

Study some of the unseen construction methods for Hadamard matrices and spend also some time studying in greater detail the methods you met in Letter 2C.
The Existence of MOLS for n 1,2 and 6.
When Euler realised that there is not a pair of MOLS of order 2 and he could not find a pair of order 6 to solve The 36 Officers Problem, he conjectured that there exists no pair of MOLS of order n when n = 2 (mod 4).
This conjecture was killed off for good in 1960 by Bose, Parker and Shrikhande, who proved that there is a pair of MOLS of order n for any n > 6. Their proof can be found in Chapter 13 of
Marshall Hall Jr. : Combinatorial Theory (Wiley 1986)
Study this proof and give a sketch of it in your seminar.

49. Math WWW VL: Specialized Fields [FSU Math]
Fixed Point Theory. four colour theorem A new proof of the four colourtheorem that uses group theory and Steiner systems. Fractals.
http://web.math.fsu.edu/Science/Specialized/
208 Love Building Tallahassee, FL 32306-4510 Phone: (850) 644-2202 Fax: (850) 644-4053 Home Virtual Library Print Math WWW VL: Specialized Fields
Home

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about the Virtual Library: Information categorized by subject. To suggest an addition to the Mathematics Virtual Library please fill out the on-line form Overseas users may want to try our mirror in Israel , hosted by the Israel Institute of Technology This collection of Mathematics-related resources is maintained by the Florida State University Department of Mathematics as a free service to the online community.
Specialized Fields of Mathematics Additional sub categories:
Numerical Analysis/
Statistics/ Alan Waldron's Homepage Theories dealing with Communist and Democratic income differences Algebraic Number Theory Archives Algebraic Topology Discussion List Application-oriented Algorithmic Mathematics (Mathematical Software NetLib, Reduce Network Library, CodeLib,A-Digest for Numerical Analysis, Opt-Net Digest for Mathematical Optimization, Information from SIG Computeralgebra and Opt-Net...) Applied Management Science: Making Good Decisions contains notes and links on the methodology of management science, optimization, linear programming, decision analysis and formulation of network problems

50. Dictionary Contents: F
forms; formula; forward analysis; forward chaining; FOT; Foucault Michel; FoucherSimon; foundation; four colour map theorem; four colour theorem; Fourier Jean
http://lgxserver.uniba.it/lei/foldop/contents/F.html
Free On-line Dictionary of Philosophy fact facticity factor Free On-line Dictionary of Philosophy fact facticity factor ... fuzzy subset

51. Four Color Theorem Intro
Thomas). Also see Nancy Casey Four Color Theorem and The MacTutorHistory of Mathematics archive - four colour theorem. Addendum
http://www.jimloy.com/geometry/4color.htm
Return to my Mathematics pages
Go to my home page
Four Color Theorem Intro
We have all seen maps in which adjacent countries (or areas) are colored with different colors, so we can easily see the boundaries between them. Mathematicians asked, "Just how many colors are necessary?" They weren't trying to help out the map makers who occasionally bungle the job (I have seen several maps with mistakes in the coloring). The mathematicians found this an interesting, and diabolically difficult puzzle. Of course, the Four Color Theorem (previously called the Four Color Conjecture) was recently proven (by Wolfgang Haken and Kenneth Appel using a super computer at the University of Illinois, in 1976), showing that four colors is all you ever need, on a plane map. That proof is very long, and I will not show it. Instead, let's prove a "three color theorem:" Three color theorem - More than three colors are required for some map or maps. Proof: Look at the diagram, above left. Can't color it with just three colors, can you? That was a little informal. But, that is essentially the proof. We wanted to show that three colors were not enough for some map. All we have to do is show a map that requires four colors, and we have proved our conjecture. I could have given some reasoning why you can't color this map with three colors. But it should be fairly obvious.

52. No Match For Four Causes
Nearby terms Foucault Michel « Foucher Simon « foundation « four colour maptheorem » four colour theorem » Fourier Jean Baptiste Joseph » Fourier
http://www.swif.uniba.it/lei/foldop/foldoc.cgi?four causes

53. Scientific Computing World: Software Reviews
I particularly enjoyed the sections on prime numbers, calculating pi,chaos, and the four colour theorem. In this last section, Kempe's
http://www.scientific-computing.com/review3b.html
home Subscribe for free news reviews ... about us
a brief history of maths
Brian Cogan reviews The Mathematical Explorer, an unusual piece of educational software
I first encountered The Mathematical Explorer under what were ideal circumstances for me - recuperating in bed after minor surgery. I loaded the program on to my laptop with a complete absence of guilt. I spent much of the next couple of days visiting many of the famous problems in the history of mathematics, learning about the people who solved them (and those who failed) and exploring the application of ideas such as Turtle fractalisation and public-key cryptography. Professor Stan Wagon, a Mathematica expert and celebrated educator and author, wrote The Mathematical Explorer. He has included topics varying in difficulty from the Riemann Hypothesis to games from recreational mathematics. The front-end is the familiar Mathematica Help browser. A scaled down Kernel is included so I didn't need any additional software to execute the numerous examples or plot graphs etc. Each of the 16 main sections ends with examples and solutions and suggestions for finding further information, with references to books, articles and links to web sites. There are also links to the web-based version of Stephen Wolfram's The Mathematica Book. Famous solved problems as well as some unsolved problems are described as well as much discussion of topics such as chaos theory, fractals, prime numbers, methods for calculating pi etc. There are many cultural and historical details included.

54. The History Of The Four Color Problem
Background information with some neat activities linked. The relationshipto South Africa. The four colour theorem; The Four Color Theorem.
http://www.geom.umn.edu/~zarembe/hist4.html
The History of the Four Color Map Problem
What is the largest possible chromatic number?
This question has puzzled mathaticians for a very long time. Hopefully you didn't spend too much time looking for a graph with a chromatic number of 5 since it has now been proved that any graph will have a chromatic number of at most 4. This is called the Four Color Problem Map makers have known for a very long time that it only takes four colors to color a map so that none of the borders have the same color. In 1852, Francis Guthrie became intrigued by this and wanted to prove it. He passed the problem along to his brother, who then asked his profesor, DeMorgan. Over time, there were many conjectures and proofs offered to show that this was true. Even mathematicians make errors though and many flaws were found. In 1976 Appel and Heken developed a proof that has so far stood the test of time. The proof uses a computer and takes up a whole book. Heken has taken bets on the validity of their proof, so far he has won.
For more historical information you may visit these websites:
  • Background information with some neat activities linked.

55. The Info Service
Poetry Challenge Fixed Point Theory on the Web Four Color Theorem gatech.edu FourColor Theorem - uidaho.edu four colour theorem - st-and.ac.uk Four Colour
http://info-s.com/math.html
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56. Mediaalert.html
December, 1999. The four colour theorem Another Way? Professor DerekHolton, University of Otago 23 pm, Monday 10 January, 2000.
http://www.edfac.unimelb.edu.au/DSME/maths2000/Festival highlights.html
MATHEMATICS 2000 FESTIVAL MEDIA HIGHLIGHTS
FOR IMMEDIATE RELEASE December, 1999 Mathematics: Its Scope, Its Beauty, and Its Depth Professor Sir Roger Penrose, University of Oxford
10-11:30 am, Monday 10 January, 2000 Maths is intrinsically beautiful, according to Roger Penrose. In his public lecture, the Professor uses a variety of simple but illuminating examples of the beauty of maths as well as its truth, breadth, utility and depth.
Media note: Key speakers are available for interview. For interview arrangements please contact: Diana Wolfenden Ph (03) 9645 0975 Mobile: 0419 547 270
Email: wolfgirl@a1.com.au
MATHEMATICS 2000 FESTIVAL MEDIA HIGHLIGHTS
FOR IMMEDIATE RELEASE December, 1999 The Maths of Car Crashes Sergeant Peter Bellion, Accident Investigation Section, Victoria Police
12-12:30 pm, Monday 10 January, 2000 Beware the speedy driver who deliberately underestimates his or her impact speed in a car accident. Peter Bellion unravels the ëforensicsí of car accidents and shows how impact speed can be correctly assessed from measurements of skid marks.
Peter has been attached to the Accident Investigation Section of the Victoria Police for nine years. He has provided expert witness reports and testimony for the investigation and reconstruction of at least 500 fatal or life threatening injury collisions. Peter also assists the Transport Accident Commission with technical expertise for their advertisements.

57. Four Colour Map Theorem From FOLDOC
four colour map theorem. mathematics, application (Or four colourtheorem ) The theorem stating that if the plane is divided into
http://wombat.doc.ic.ac.uk/foldoc/foldoc.cgi?four colour map theorem

58. A New Proof Of The Four-Colour Theorem
A new proof of the fourcolour theorem. Neil Robertson, Daniel P. Sanders,Paul Seymour, and Robin Thomas. Abstract. The four-colour
http://www.mpim-bonn.mpg.de/external-documentation/era-mirror/1996-01-003/1996-0
This journal is archived by the American Mathematical Society. The master copy is available at http://www.ams.org/era/
A new proof of the four-colour theorem
Neil Robertson, Daniel P. Sanders, Paul Seymour, and Robin Thomas
Abstract.
    The four-colour theorem, that every loopless planar graph admits a vertex-colouring with at most four different colours, was proved in 1976 by Appel and Haken, using a computer. Here we announce another proof, still using a computer, but simpler than Appel and Haken's in several respects.
Retrieve entire article
Article Info
  • ERA Amer. Math. Soc. (1996), pp. 17-25 Publisher Identifier: S 1079-6762(96)00003-5 Mathematics Subject Classification . Primary 05C10, 05C15, 05C85 Received by the editors September 26, 1995 Communicated by Ronald Graham Comments (When Available)
Neil Robertson Department of Mathematics, Ohio State University, 231 W. 18th Ave., Columbus, Ohio 43210, USA E-mail address: robertso@math.ohio-state.edu Daniel P. Sanders School of Mathematics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
E-mail address: dsanders@math.ohio-state.edu

59. Electronic Research Announcements Of The AMS
n$simplex 05C10 Neil Robertson; Daniel P. Sanders; Paul Seymour;Robin Thomas A new proof of the four-colour theorem. 05C15 Neil
http://www.mpim-bonn.mpg.de/external-documentation/era-mirror/era-msc-1996.html
This journal is archived by the American Mathematical Society. The master copy is available at http://www.ams.org/era/
1996 Table of Contents - Indexed by Math Subject Classification
Ricardo Diaz; Sinai Robins
The Ehrhart polynomial of a lattice $n$-simplex
Neil Robertson; Daniel P. Sanders; Paul Seymour; Robin Thomas
A new proof of the four-colour theorem
Neil Robertson; Daniel P. Sanders; Paul Seymour; Robin Thomas
A new proof of the four-colour theorem
Neil Robertson; Daniel P. Sanders; Paul Seymour; Robin Thomas
A new proof of the four-colour theorem
Ricardo Diaz; Sinai Robins
The Ehrhart polynomial of a lattice $n$-simplex
Ricardo Diaz; Sinai Robins
The Ehrhart polynomial of a lattice $n$-simplex
Ricardo Diaz; Sinai Robins
The Ehrhart polynomial of a lattice $n$-simplex
Carlos A. Berenstein; Alain Yger
Residues and effective Nullstellensatz
Carlos A. Berenstein; Alain Yger
Residues and effective Nullstellensatz
Ricardo Diaz; Sinai Robins
The Ehrhart polynomial of a lattice $n$-simplex
Ricardo Diaz; Sinai Robins The Ehrhart polynomial of a lattice $n$-simplex Carlos A. Berenstein; Alain Yger

60. OUP: Graphs, Colourings And The Four-Colour Theorem: Wilson
Graphs, colourings and the fourcolour theorem. Introductory and wellpaced explanations of the proof of the four-colour theorem.
http://www.oup.co.uk/isbn/0-19-851062-4
VIEW BASKET Quick Links About OUP Career Opportunities Contacts Need help? oup.com Search the Catalogue Site Index American National Biography Booksellers' Information Service Children's Fiction and Poetry Children's Reference Dictionaries Dictionary of National Biography Digital Reference English Language Teaching Higher Education Textbooks Humanities International Education Unit Journals Law Medicine Music Oxford English Dictionary Reference Rights and Permissions Science School Books Social Sciences World's Classics UK and Europe Book Catalogue Help with online ordering How to order Postage Returns policy ... Table of contents
Graphs, Colourings and the Four-Colour Theorem
Robert A. Wilson , Professor of Group Theory, The University of Birmingham
Publication date: 24 January 2002
150 pages, numerous figures, 234mm x 156mm
There is an alternative edition (Hardback)
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A sample of this book
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  • Over 100 diagrams illustrating and clarifying definitions and proofs, etc

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