quotient mapping造句

• Quotient mapping and quotient topology
  商映射与商空间
• Fairly important covers have point - countable bases , weakly bases , k - networks , sequence - neighbourhood networks and so on . fairly important mappings have quotient s - mappings , closed s - mappings , open mappings , open - and - closed mappings , com - pact - and - open mappings , perfect mappings , countable bi - quotient mappings , compact mappings
  比较重要的覆盖有点可数基，弱基， k网，序列邻域网；比较重要的映射有商s映射，闭s映射，开映射，开闭映射，紧开映射，完备映射，可数双商映射，紧映射。