1. Novosibirsk State University , Pirogova str. 1 , Novosibirsk , 630090; and Sobolev Institute of Mathematics, prosp. Koptyuga 4, Novosibirsk 630090; and Novosibirsk State Agrarian University, Dobrolyubova street, 160, Novosibirsk, 630039; and Regional Scientific and Educational Mathematical Center of Tomsk State University, 36 Lenin Ave., Tomsk , Russia
2. Département des Sciences Mathématiques , Université Montpellier II , Place Eugène Bataillon, 34095 Montpellier cedex 5 , France ; and Sobolev Institute of Mathematics, Novosibirsk 630090, Russia
3. Center for Topology and Geometry based Technology , Hebei Normal University , No. 20 Road East, 2nd Ring South, Yuhua District, Shijiazhuang , Hebei , 050024; and School of Mathematical Sciences, Hebei Normal University, No. 20 Road East, 2nd Ring South, Yuhua District, Shijiazhuang, Hebei, 050024 P. R. China