Protasov, I. V.(ДЗ "ЛНУ імені Тараса Шевченка", 2019)
In this paper, exact sequences of graphs are
defined and investigated. Considering some functors on the category
of graphs, we study some conditions to determine exactness of
functors.
Protasov, I. V.(ДЗ "ЛНУ імені Тараса Шевченка", 2019)
Semiabelinan flocks and n-ary groups are charac-
terized by the properties of parallelograms and vectors of the affine
geometry defined by these flocks and n-ary groups.