Nguyen Tien Quang, Pham Thi Cuc, and Nguyen Thu Thuy Hanoi National University of Education, Hongduc University, Academy of Finance, Science Faculty
Abstract : In this paper we state some applications of Gr-category theory to the classification problem of crossed modules and to that of group extensions of the type of a crossed module.
Keywords : crossed module, Gr-category, group extension, group cohomology, obstruction
