1. A Semigroup of Theories and Its Lattice of Idempotent Elements

   • M. I. Bekenov
   • A. M. Nurakunov

   OriginalPaper 15 June 2021 Pages: 1 - 14

2. Piecewise Monotonicity for Unary Functions in o-Stable Groups

   • V. V. Verbovskiy
   • A. B. Dauletiyarova

   OriginalPaper 15 June 2021 Pages: 15 - 25

3. Characterizations of ITBM-Computability. II

   • P. Koepke
   • A. S. Morozov

   OriginalPaper 15 June 2021 Pages: 26 - 37

4. Topologies, Ranks, and Closures for Families of Theories. II

   • N. D. Markhabatov
   • S. V. Sudoplatov

   OriginalPaper 12 June 2021 Pages: 38 - 52

5. A Basis for the Commutator Subgroup of a Partially Commutative Metabelian Pro-p-Group

   • E. I. Timoshenko

   OriginalPaper 12 June 2021 Pages: 53 - 63

6. Interpreting the Action of the Endomorphism Monoid of the Rationals

   • J. K. Truss
   • E. Vargas-García

   OriginalPaper 17 June 2021 Pages: 64 - 74

7. Sessions of the Seminar “Algebra i Logika”

   Acknowledgments 15 June 2021 Pages: 75 - 77