“四色问题”的探索与论证

his paper based on the previous definition, axiom and theorem about graph theory to demonstrate the four-color problem. Firstly, I made a summary about the necessary theory, and listed all of the definition, axiom and theorem, which involved in the demonstration. Secondly, through two methods of adding vertex and line into maximal planar graph, to demonstrate that the chromatic number of every maximal planar graph is not bigger than four; Lastly, by adding vertex and line into planar graph to construct maximal planar graph, to demonstrate that the chromatic number of every planar graph is not bigger than four, then, completed the demonstration of the four-color problem.