an:05833234
Zbl 1221.05165
Steinberger, John P.
An unavoidable set of \(D\)-reducible configurations
EN
Trans. Am. Math. Soc. 362, No. 12, 6633-6661 (2010).
00271662
2010
j
05C15
graph theory; four-color theorem
Summary: We give a new proof of the four-color theorem by exhibiting an unavoidable set of 2822 \(D\)-reducible configurations. The existence of such a set had been conjectured by several researchers including Stromquist (1975), Appel and Haken (1977), and Robertson, Sanders, Seymour and Thomas (1997).