Computability in Europe 2006
Logical Approaches to Computational Barriers

Regular Talk:
Cupping Classes of Sigma 2 Enumeration Degrees

Speaker: Mariya Ivanova Soskova
Slot: Array, 11:40-12:00, col. 3


We prove that no subclass of the Sigma 2 enumeration degrees
containing the 3-c.e. enumeration degrees can be cupped to 0'e by a
single Sigma 2 enumeration degree.

websites: Arnold Beckmann 2008-05-19