Authors
Citation
P. Cholak et al., An almost deep degree, J SYMB LOG, 66(2), 2001, pp. 881-901
Citations number
3
Categorie Soggetti
Mathematics
Journal title
JOURNAL OF SYMBOLIC LOGIC
ISSN journal
00224812
→ ACNP
Volume
66
Issue
2
Year of publication
2001
Pages
881 - 901
Database
ISI
SICI code
0022-4812(200106)66:2<881:AADD>2.0.ZU;2-6
Abstract
We show there is a non-recursive r.e. set A such that if W is any low r.e.
set, then the join W circle plus A is also low. That is A is "almost deep".
This answers a question of Jockusch. The almost deep degrees form an defin
able ideal in the r.e. degrees (with jump.).