four-color problem
[ fawr-kuhl-er, fohr- ]
/ ˈfɔrˈkʌl ər, ˈfoʊr- /
noun Mathematics.
the problem, solved in 1976, of proving the theorem that any geographic map can be colored using only four colors so that no connected countries with a common boundary are colored the same color.
Also called
four-color theorem.
Origin of four-color problem
First recorded in 1875–80
Words nearby four-color problem
four-banger,
four-by-four,
four-by-two,
four-channel,
four-color,
four-color problem,
four-colour,
four-corners,
four-cycle,
four-deal bridge,
four-dimensional