R.D. Shuvalov1, E.A. Sidorova2

1 Novosibirsk State University (Novosibirsk, Russia)
2 A.P. Ershov Institute of Informatics Systems, Siberian Branch of the Russian Academy of Sciences (Novosibirsk, Russia)
1 r.shuvalov@g.nsu.ru, 2 lsidorova@iis.nsk.su