1. Institute of Mathematics “Simion Stoilow” of the Romanian Academy Bucharest Romania
2. Academy of the Romanian Scientists Bucharest Romania
3. Department of Computing, Mathematics and Electronics “1 Decembrie 1918” University of Alba Iulia Alba Iulia Romania
4. Faculty of Mathematics and Computer Science Transilvania University of Braşov Braşov Romania
5. Université de Lorraine CRAN, UMR 7039, Campus Sciences, BP 70239 Vandoeuvre‐les‐Nancy Cedex France
6. CNRS CRAN UMR France