This paper extends Post’s programme to finite levels of the Ershov hierarchy of ∆2 sets. Our initial characterisation, in the spirit of Post [27], of the degrees of the immune...
Bahareh Afshari, George Barmpalias, S. Barry Coope...
We enumerate all totally real number fields F with root discriminant F 14. There are 1229 such fields, each with degree [F : Q] 9. In this article, we consider the following prob...
We study the minimal enumeration degree (e-degree) problem in models of fragments of Peano arithmetic (PA) and prove the following results: In any model M of 2 induction, there is ...
Marat M. Arslanov, Chi Tat Chong, S. Barry Cooper,...
Let S be a set of n points in IRd and let t > 1 be a real number. A t-spanner for S is a graph having the points of S as its vertices such that for any pair p, q of points ther...
We say that A LR B if every B-random number is A-random. Intuitively this means that if oracle A can identify some patterns on some real , oracle B can also find patterns on . In o...
George Barmpalias, Andrew E. M. Lewis, Mariya Ivan...