KnowraFour color theoremLinked fromLinked fromThe 15 pages that link to Four color theorem, each with the reason it gives.All 15Broader topic 5Related 7Compared with 3Five color theoremCompared with: It sharpens the five-color upper bound by one color.Heawood conjectureCompared with: For genus zero, the conjectured expression overshoots the true planar maximum.De Bruijn–Erdős theorem (graph theory)Compared with: It proves a finite-color bound for planar graphs, while De Bruijn–Erdős transfers finite checks to infinite graphs.