Everywhere Nonrecursive r.e. Sets in Recursively Presented Topological Spaces

Journal of the Australian Mathematical Society

Li Xiang¹ 

关键词: 03 D 45;    54 A 05;   

DOI  :  10.1017/S1446788700031402

学科分类：数学（综合）

来源: Cambridge University Press

【 摘 要 】

Recursively presented topological spaces are topological spaces with a recursive system of basic neighbourhoods. A recursively enumerable (r.e.) open set is a r.e. union of basic neighbourhoods. A set is everywhere r.e. open if its intersection with each basic neighbourhood is r.e. Similarly we define everywhere creative, everywhere simple, everywhere r.e. non-recursive sets and show that there exist sets both with and without these everywhere properties.

【 授权许可】

Unknown