On the semigroup of fully indecomposable relations
On the semigroup structure of cyclic left distributive algebras.
On the topological structure of a finitely generated semigroup of matrices.
On the weak permutation property.
On the word problem for free bands of groups and for free objects in some other varieties of completely regular semigroups.
On the word problem for free completely regular semigroups.
On two problems related to cancellativity.
On uniformly repetitive semigroups.
On universal quasigroup identities
The paper deals with quasigroup identities under isotopies. The terminology is taken from [2], [3] and [4]. Stimulated by geometric illustrations, V. D. Belousov in [2] has presented two important identity properties and posed a question for which identities these properties are necessary and sufficient for the identity to be invariant under isotopies. Inspired by V. D. Belousov, G. Monoszová investigated in [6] one special kind of identities for which both Belousov’s properties give necessary and...
On V n -semigroups
In this paper, we give some new characterizations of orthodox semigroups in terms of the set of inverses of idempotents. As a generalization, a new class of regular semigroups, namely Vn-semigroups, is introduced. Also, we give a characterization of Vn-semigroups and investigate some properties of Vn-semigroups. Furthermore, we show that the class of Vn-semigroups is closed under direct products and homomorphic images. However, regular subsemigroups of Vn-semigroups (n ≥ 2) are not necessarily Vn-semigroups...
On varieties of combinatorial inverse semigroups II.
Operators , and in the classes of -semigroups and -semirings.
Ordering D-classes and computing Schein rank is hard.
Partially abelian squarefree words
Periodic endomorphisms of a free monoid.
Permutability of normal extensions of a semilattice.
Permutation functions and (n,m)-commutativity of semigroups .
Permutation properties and the Fibonacci semigroup.
Positive functions from -indecomposable semigroups into partially ordered sets
Pour le monoïde plaxique
Cet article est probablement le dernier texte de mathématiques écrit en vue de sa publication par M. P. Schützenberger, décédé en juillet 1996. Il était offert par son auteur en hommage à André Lentin, à l'occasion d'un colloque tenu en l'honneur de celui-ci le 23 février 1996 ; M. P. Schützenberger, déjà très malade, n'avait pu participer à cette rencontre, mais avait tenu à rédiger, non sans souffrances, une contribution scientifique qui témoignât de son amitié pour A. Lentin. Lorsque je lui dis...