Effective embeddings into strong degree structures
β Scribed by Timothy H. McNicholl
- Publisher
- John Wiley and Sons
- Year
- 2003
- Tongue
- English
- Weight
- 215 KB
- Volume
- 49
- Category
- Article
- ISSN
- 0044-3050
No coin nor oath required. For personal study only.
β¦ Synopsis
Abstract
We show that any partial order with a Ξ£~3~ enumeration can be effectively embedded into any partial order obtained by imposing a strong reducibility such as β€~tt~ on the c. e. sets. As a consequence, we obtain that the partial orders that result from imposing a strong reducibility on the sets in a level of the Ershov hiearchy below Ο + 1 are coβembeddable.
π SIMILAR VOLUMES
We present a necessary and su cient condition for the embeddability of a principally decomposable ΓΏnite lattice into the computably enumerable degrees. This improves a previous result which required that, in addition, the lattice be ranked. The same condition is also necessary and su cient for a ΓΏni