I. P. Los
Belarusian State University; Institute of Mathematics of the National Academy of Sciences of Belarus
Belarus

Inna P. Los – Postgraduate Student; Junior Researcher

4, Nezavisimosti Ave., 220030, Minsk;

11, Surganov Str., 220072, Minsk

V. G. Safonov
Institute of Mathematics of the National Academy of Sciences of Belarus;Belarusian State University
Belarus

Vasily G. Safonov – Dr. Sc. (Physics and Mathematics), Professor, Director; Chief Researcher

11, Surganov Str., 220072, Minsk;

4, Nezavisimosti Ave., 220030, Minsk