*定義 [#bab41065] Let E be a family of subsets in a topological space. E is said to have a fip (the finite intersection property) if and only if every finite subfamily of E has a nonempty intersection.
*定義 [#bab41065] Let E be a family of subsets in a topological space. E is said to have a fip (the finite intersection property) if and only if every finite subfamily of E has a nonempty intersection.