Determining concepts by group membership (Q1181005)

This paper has two parts: the first part consists of the presentation of an algorithm which decides whether an element of a finite abelian group belongs to a given subgroup of the group. This algorithm, based on an algorithm by \textit{R. Laue}, \textit{J. Neubüser} and \textit{U. Schoenwaelder} [Computational Group Theory, Proc. Symp., Durham 1982, 105--135 (1984; Zbl 0547.20012)] is better adapted to the situation in which the subgroup in question changes rather infrequently. The second part of the paper presents the motivation of the algorithm, which comes from genetic search and gives an example which proves that in some circumstances one can decide that two elements of a given context are related by a concept if one identifies the context with a given finite abelian group and the concept with one of its subgroups.