【摘要】 给出了覆盖的概念 ,讨论了一个不等式 ,利用不等式证明了Tr<2 ,不存在各模最小公倍数无平方因子且仅有r个不同素因子的奇覆盖系更多还原

【Abstract】 An inequality about covering system is given in this paper .By using the inequality, some properties of an add covering system and some necessary conditions for the existence of the system were proved. Some example are given to make our results clear.更多还原