Аннотация:
In this paper new criteria of semi-commutativity and results on self-coincidence of an arbitrary point $P$ in the terms of properties of vectors of $n$-ary groups are obtained.
Ключевые слова:Semi-abelian $n$-ary group, self-coincidence of points (elements), symmetric points, a parallelogram of an $n$-ary group, vectors of $n$-ary groups.