We established the concept of a binary reflexive relation of adjacency and determined the
algebraic system consisting of all binary relations of set X and all unordered pairs of binary …

Among the unsolved problems of enumeration of graphs, one of the most difficult is the
problem of enumeration of transitive digraphs, which is equivalent to the problem of …

In two previous works of the author, published in this journal, a series of formulas are
obtained related to the themes of enumeration of partial orders (finite topologies). In the first …