All a b c d e f g h i j k l m n o p q r s t u v w x y z Other

Previous Page 29 Next

Displaying 561 – 580 of 834

Showing per page

Structures naturelles des demi-groupes et des anneaux réguliers ou involutés

Jean Calmes (1994)

Mathématiques et Sciences Humaines

Certaines relations binaires sont définies sur les demi-groupes et les demi-groupes à involution. On examine comment elles peuvent en ordonner les éléments: notamment les idempotents, les éléments réguliers au sens de von Neumann, ceux qui possédent un inverse ponctuel ou de Moore-Penrose ; et en fonction aussi de conditions sur l'involution. Ces relations peuvent alors coïncider avec les ordres naturels des idempotents et des demi-groupes inverses, avec les ordres de Drazin et de Hartwig : elles...

Sturdy bands of semigroups.

Miroslav Ciric, Stojan Bogdanovic (1990)

Collectanea Mathematica

In this paper we consider band compositions determined by two transitive systems of monomorphisms, called the sturdy bands of semigroups.

Sturdy frames of type (2,2) algebras and their applications to semirings

X. Z. Zhao, Y. Q. Guo, K. P. Shum (2003)

Fundamenta Mathematicae

We introduce sturdy frames of type (2,2) algebras, which are a common generalization of sturdy semilattices of semigroups and of distributive lattices of rings in the theory of semirings. By using sturdy frames, we are able to characterize some semirings. In particular, some results on semirings recently obtained by Bandelt, Petrich and Ghosh can be extended and generalized.

Su certe classi di gruppi unipotenti

G. Falcone (2005)

Bollettino dell'Unione Matematica Italiana

Si presentano alcuni risultati che caratterizzano i gruppi algebrici unipotenti aventi come reticolo dei sottogruppi connessi una catena e si discutono alcuni risultati conseguenti.

Su di un problema combinatorio in teoria dei gruppi

Mario Curzio, Patrizia Longobardi, Mercede Maj (1983)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni

Let G be a group and n an integer ≥ 2 . We say that G has the n -permutation property ( G ∈ P n ) if, for any elements x 1 , x 2 , ⋯ , x n in G , there exists some permutation σ of { 1 , 2 , ⋯ , n } , σ ≠ i ⁢ d . such that x 1 , x 2 , ⋯ , x n = x σ ⁢ ( 1 ) , x σ ⁢ ( 2 ) , ⋯ , x σ ⁢ ( n ) . We prouve that every group G ∈ P n is an FC-nilpotent group of class ≤ n - 1 , and that a finitely generated group has the n -permutation property (for some n ) if, and only if, it is abelian by finite. We prouve also that a group G ∈ P 3 if, and only if, its derived subgroup has order at most 2.

Su una classe di gruppi finiti supersolubili

Alma D’Aniello (1984)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni

In this paper we study the class of finite groups G whose nilpotent residual is a Hall subgroup having all subgroups normal in G .

Currently displaying 561 – 580 of 834