26 citations · 39 across the 6 of their papers we have counts for
6 papers · 1 filter
Degrees that are not degrees of categoricity
Bernard A. Anderson, Barbara F. Csima
A computable structure A is x-computably categorical for some Turing degree x, if for every computable structure B isomorphic to A there is an isomorphism f:B -> A with f computabl…
A bounded jump for the bounded Turing degrees
Bernard A. Anderson, Barbara F. Csima
We define the bounded jump of A by A^b = {x | Exists i <= x [phi_i (x) converges and Phi_x^[A|phi_i(x)](x) converges} and let A^[nb] denote the n-th bounded jump. We demonstrate se…
Partitions of trees and ACA'
Bernard A. Anderson, Jeffry L. Hirst
We show that a version of Ramsey's theorem for trees for arbitrary exponents is equivalent to the subsystem ACA' of reverse mathematics.
Automorphisms of the truth-table degrees are fixed on some cone
Bernard A. Anderson
Let Dtt denote the set of truth-table degrees. A bijection p from Dtt to Dtt is an automorphism if for all truth-table degrees x and y we have x <=tt y if and only if p(x) <=tt p(y…
Relatively computably enumerable reals
Bernard A. Anderson
A real X is defined to be relatively c.e. if there is a real Y such that X is c.e.(Y) and Y does not compute X. A real X is relatively simple and above if there is a real Y <_T X s…
Reals n-generic relative to some perfect tree
Bernard A. Anderson
We say that a real X is n-generic relative to a perfect tree T if X is a path through T and for all Sigma^0_n (T) sets S, there exists a number k such that either X|k is in S or fo…