Soon after his 1964 seminal paper on edge colouring, Vizing asked the following question: can an optimal edge colouring be reached from any given proper edge colouring through a series of Kempe changes? We answer this question in the affirmative for triangle-free graphs.
翻译:在1964年关于边缘颜色的开创性论文发表后不久,维京提出以下问题:通过一系列的Kempe变化,任何给定的适当边缘颜色都能达到最佳边缘颜色吗?我们用对无三角图的肯定回答这个问题。