Coloring in Space
摘要
When in 1958, Paul Erdős learned about the chromatic number of the plane problem, he created a number of related problems, some of which we have discussed in the preceding chapters. Paul also generalized the problem to the n-dimensional Euclidean spaces En. On October 2, 1991, I received a letter from him, which contained a historic remark [E91/10/2ltr]: