Wu Guohua Nanyang Technol Univ Div Math Sci Sch Phys & Math Sci Singapore 637371 Singapore. Liu Jiang Chinese Acad Sci Inst Software State Key Lab Comp Sci Beijing 100190 Peoples R China.
In this paper, we study the cupping property in the d.r.e. degrees, and prove the existence of a d.r.e. degrees d with almost universal cupping property and nonzero r.e. degrees b < d and a such that b isolates d in the d.r.e. degrees, and b and a form a minimal pair. As a corollary, we have that for any nonzero r.e. degree c <= a and incomplete d.r.e. degree e >= d, 0, c, e and 0' form a diamond embedding in the d.r.e. degrees. (c) 2011 Elsevier B.V. All rights reserved.
English Abstract:
In this paper, we study the cupping property in the d.r.e. degrees, and prove the existence of a d.r.e. degrees d with almost universal cupping property and nonzero r.e. degrees b < d and a such that b isolates d in the d.r.e. degrees, and b and a form a minimal pair. As a corollary, we have that for any nonzero r.e. degree c <= a and incomplete d.r.e. degree e >= d, 0, c, e and 0' form a diamond embedding in the d.r.e. degrees. (c) 2011 Elsevier B.V. All rights reserved.