An extension of Harrington's noncupping theorem

被引:1
|
作者
Yu, L [1 ]
Ding, DC [1 ]
机构
[1] Nanjing Univ, Dept Math, Nanjing 210093, Peoples R China
来源
关键词
anti-cupping property; noncuppable; high T-degrees; computably enumerable set;
D O I
10.1360/03yf9017
中图分类号
TP [自动化技术、计算机技术];
学科分类号
0812 ;
摘要
(1) Call a c.e. degree b anti-cupping relative to x, if there is a c.e. a < b such that for any c.e. w, w not greater than or equal to x implies a U w not greater than or equal to b U x. (ii) Call a c.e. degree b everywhere anti-cupping (e.a.c.), if it is anti-cupping relative to x for each c.e. degree x. By a tree method, we prove that every high c.e. degree has e.a.c. property by extending Harrington's anti-cupping theorem.
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页码:199 / 209
页数:11
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