Projectivity of acts and Morita equivalence of monoids.
Projektive Klassen endlicher Gruppen. I. Schunck- und Gaschützklassen.
Projektivitätstypen torsionsfreier abelscher Gruppen vom Rang 1
Pronormal and subnormal subgroups and permutability
We describe the finite groups satisfying one of the following conditions: all maximal subgroups permute with all subnormal subgroups, (2) all maximal subgroups and all Sylow -subgroups for permute with all subnormal subgroups.
Pronormality, contranormality and generalized nilpotency in infinite groups.
This article is dedicated to some criteria of generalized nilpotency involving pronormality and abnormality. Also new results on groups, in which abnormality is a transitive relation, have been obtained.
Proof of the Parthasarathy-Ranga Rao-Varadarajan conjecture.
Proof of Verma's Conjecture on Weyl's Dimension Polynomial.
Proper left type- covers.
Proper periods of normal N.E.C. subgroups with even index.
By a non-Euclidean crystallographic (N.E.C.) group we shall mean a discrete subgroup Γ of isometries of the non-Euclidean plane including those reverse orientation, reflections and glide-reflections.In [1] we computed the proper periods of normal N.E.C. subgroups of an N.E.C. group, when the index of the group with respect to the subgroup is odd. In this paper we shall compute the proper period of normal N.E.C. subgroups, when the index is even.The corresponding problem for Fuchsian groups, which...
Properties of a pair of functions which generate a dense subsemigroup of S(X).
Properties of congruences on commutative monoids.
Properties of digraphs connected with some congruence relations
The paper extends the results given by M. Křížek and L. Somer, On a connection of number theory with graph theory, Czech. Math. J. 54 (129) (2004), 465–485 (see [5]). For each positive integer define a digraph whose set of vertices is the set and for which there is a directed edge from to if The properties of such digraphs are considered. The necessary and the sufficient condition for the symmetry of a digraph is proved. The formula for the number of fixed points of is established....
Properties of element orders in covers for and .
Properties of subgroups not containing their centralizers
In this paper, we give a generalization of Baer Theorem on the injective property of divisible abelian groups. As consequences of the obtained result we find a sufficient condition for a group to express as semi-direct product of a divisible subgroup and some subgroup . We also apply the main Theorem to the -groups with center of index , for some prime . For these groups we compute the number of conjugacy classes and the number of abelian maximal subgroups and the number of nonabelian...
Properties of the subsemigroups of the bicyclic monoid
In this paper we study some properties of the subsemigroups of the bicyclic monoid B, by using a recent description of its subsemigroups. We start by giving necessary and sufficient conditions for a subsemigroup to be finitely generated. Then we show that all finitely generated subsemigroups are automatic and finitely presented. Finally we prove that a subsemigroup of B is residually finite if and only if it does not contain a copy of B.
Propriétés des demi-groupes de fractions
Propriétés des demi-groupes de fractions
Propriétés générales des substitutions à une variable et des fonctions qu'elles laissent invariables
Propriétés nouvelles des tableaux de Young
Protomodularity, descent, and semidirect products.