非半临界度及其亚稠密性

ON NONSIMICONTIGUOUS DEGREE AND ITS QUASI-DENSITY

临界度、半临界度有着很好的归约性质,因而在递归可枚举度的研究中占有重要的地位。本文考察这些问题的反面——非半临界度,我们给出一个非半临界度的简单易行的构造方法,并利用这个方法给出这种度的亚稠密性。我们证明:(a) 在任意给定的度b>0上具有一个非半临界度a>b。(b) 给定任意的度b>0,b下也具有一个非半临界度a<b。

As they have very well property in reducibility. Contiguous degrees and simi contiguous degrees play an impotant role in reserching of recursively enumerable degrees. In this paper, We consider the contrary of these questions——the nonsimi contiguous degree, We give a simple construction of the nonsimi contiguons degree. Using the construction we have shown the following: (a)Given a nonzero r.e.degree (?)>(?), there exists a nonsimicontiguous degree (?)>(?). (b)Give any nonzero degree(?) >(?).there exists a nonsimicontiguous degree(?)<(?).