THE STRUCTURE OF THE UPPER BOUNDS OF THE ARITHMETICAL DEGREES
Abstract (summary)
The structure of the upper bounds for the Arithmetical Degrees of Unsolvability is studied, with emphasis on those degrees which are jumps of upper bounds.
An analogy is drawn between the set of all complete degrees and the set of uniform upper bounds of arithmetical functions, AR. A Join Theorem is proved for the degrees of uub's for AR. A Jump Inversion theorem is also proved for those degrees.
The (FOR ALL)(THERE EXISTS) theory of the degrees is shown to be decidable with a proof about extendability of poset embeddings above the arithmetical degrees.