Mathematical Logic and Its Applications 2020

The issue Mathematical Logic and Its Applications 2020 contains articles related to the following three directions: I. Descriptive Set Theory (3 articles). Solutions for long-standing problems including those of A. Tarski and H. Friedman are presented.II. Exact combinatorial optimization algorithms in which the complexity relative to the source data is characterized by a low or even first degree polynomial (1 article).III. Applications of mathematical logic and the theory of algorithms (2 articles). The first article deals with the Jacobian and M. Kontsevichs conjectures and algorithmic undecidability; for these purposes non-standard analysis is used. The second article provides a quantitative description of the balance and adaptive resource of a human.Submissions are invited for the next issue Mathematical Logic and Its Applications 2021