Appendix
摘要
Measurable sets and measure. For more information on this topic, see ( A. Katok and B. Hasselblatt. Introduction to the Modern Theory of Dynamical Systems. Cambridge University Press, 1995.; V. V. Nemytski and V. V. Stepanov. Qualitative Theory of Dynamical Systems. Princeton University Press, 1960. Russian original 1949.;). Essential Graph Theory Knowledge.