Relatively free bands

• Tipo: Artigo em Revista Científica Internacional
• Data: 2000

Autores

Mario Petrich (Autor) Outra; Pedro V. Silva (Autor) FCUP

Revista

Título: Communications in Algebra

Vol. 28 Nº 5

Páginas: 2615-2631

ISSN: 0092-7872

Editora: Taylor & Francis

Indexação

ISI Web of Knowledge - 5 Citações

ISI Web of Science

Scopus - 4 Citações

Classificação Científica

FOS: Ciências exactas e naturais > Matemática

Outras Informações

ID Authenticus: P-001-19Z

DOI: 10.1080/00927870008826982

Abstract (EN): The operators h(n) and i(n) and their duals <(h(n))over bar> and <(i(n))over bar> defined on the free semigroup X+ for a nonempty set X by Gerhard and Petrich are proved here to be homomorphisms of X+ onto certain subsets of X+ with a suitable multiplication. From the work of the authors mentioned, these operators induce fully invariant congruences on X+ corresponding to join irreducible varieties of bands if X is countably infinite. New operators on X+ are defined by means of these operators which give homomorphisms in an analogous way and induce fully invariant congruences on X+ corresponding to all varieties of bands except. For the variety of all bands, and some varieties of normal bands. The Former of these was investigated by the mentioned authors and the latter must be treated differently. By means of the above operators we are able to characterize all cases of relatively free bands.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 17