| 释义 |
second axiom of countability‘数’第二可数公理second axiom of countability第二可数[性]公设;第二可数[性]公理双向☞axiom of second countability -- second axiom of countability双向☞second axiom of countability -- second countability axiomsecond axiom of countability第二可數[性]公設;第二可數[性]公理數 |