Copyright © The Association for Symbolic Logic 2019. A structure is automatic if its domain, functions, and relations are all regular languages. Using the fact that every automatic structure is decidable, in the literature ...

The main goal of this paper is to study algorithmic properties of countable linear orders by constructing effective presentations of these structures on the set of natural numbers. In 1991, C. Jockusch and R. Soare constructed ...

This paper is a survey of results on countable families with natural degree spectra. These results were obtained by a modification of the methodology proposed by Wechner, who first found a family of sets with the spectrum ...

In this work, we review results of the last years related to the development of the structural theory of n-c.e. Turing degrees for n > 1. We also discuss possible approaches to solution of the open problems.