Algebra and Discrete Mathematics, 2013, Vol. 16, № 1
http://dspace.nbuv.gov.ua:80/handle/123456789/150379
2021-01-17T16:48:01ZJoseph Solomonovich Ponizovskii (1928 – 2012)
http://dspace.nbuv.gov.ua:80/handle/123456789/158466
Joseph Solomonovich Ponizovskii (1928 – 2012)
2013-01-01T00:00:00ZThe monoid of endomorphisms of disconnected hypergraphs
http://dspace.nbuv.gov.ua:80/handle/123456789/152316
The monoid of endomorphisms of disconnected hypergraphs
Zhuchok, Yu.V.
We prove that the monoid of endomorphisms of an arbitrary disconnected hypergraph is isomorphic to a wreath product of a transformation semigroup with a certain small category. For disconnected hypergraphs we also study the structure of the monoid of strong endomorphisms and the group of automorphisms.
2013-01-01T00:00:00ZOn one class of partition polynomials
http://dspace.nbuv.gov.ua:80/handle/123456789/152315
On one class of partition polynomials
Zatorsky, R.; Stefluk, S.
We consider relations between one class of partition polynomials, parafunctions of triangular matrices (tables), and linear recurrence relations.
2013-01-01T00:00:00ZInverse semigroups generated by group congruences. The Möbius functions
http://dspace.nbuv.gov.ua:80/handle/123456789/152314
Inverse semigroups generated by group congruences. The Möbius functions
Schwab, E.D.
The computation of the Möbius function of a Möbius category that arises from a combinatorial inverse semigroup has a distinctive feature. This computation is done on the field of finite posets. In the case of two combinatorial inverse semigroups, order isomorphisms between corresponding finite posets reduce the computation to one of the semigroups. Starting with a combinatorial inverse monoid and using a group congruence we construct a combinatorial inverse semigroup such that the Möbius function becomes an invariant to this construction. For illustration, we consider the multiplicative analogue of the bicyclic semigroup and the free monogenic inverse monoid.
2013-01-01T00:00:00Z