Definition
A Hausdorff space is called NS compact if there exists some subbase S which satisfies:
- Every cover of X by elements of S has a subbase which consists of at most two elements.
- Whenever two elements {A,B} of S cover X, there exist two disjoint elements {C,D} of S such that A∪C=B∪D=X.
Remark
- It is an abbreviation for nomally supercompact.
Reference
Zhongqiang Yang, Normally supercompact spaces and completely distributive poset, 数理解析研究所講究録 (RIMS Kokyuroku), 1107: 32-40.