ISSN:0092-7872    

DOI:10.1080/00927879308824696

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1993

数据来源: Taylor

ISSN:0092-7872    

DOI:10.1080/00927879308824697

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1993

数据来源: Taylor

摘要:

Weinberg showed that the variety of abelian lattice-ordered groups is the minimal nontrivial variety in the lattice of varieties of lattice-ordered groups. Scrimger showed that the abelian variety of lattice-ordered groups has countably infinitely many nonrepresentable covering varieties, and it is now known that his varieties are the only nonrepresentable covers of the abelian variety.

ISSN:0092-7872    

DOI:10.1080/00927879308824698

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1993

数据来源: Taylor

摘要:

Let △ be a multiplicatively closed set of finitely generated nonzero ideals of a ring R. Then the concept of a △ -reduction of anR-submoduleDof anR-moduleAis introduced and several basic properties of such reductions are established. Among these are that a minimal △ -reductionBofDexists and that every minimal basis ofBcan be extended to a minimal basis of allR-submodules betweenBandD, whenRis local andAis a finiteR-module. Then, as an application, △ -reductionsBof a submodule C with property (*) are introduced, characterized, and shown to be quite plentiful. Here, (*) means that (R ,M) is a local ring of altitude at least one, that △ = {Mn;n≥ 0} and that ifD⊆EareR-submodules betweenBandC, then every minimal basis ofDcan be extended to a minimal basis ofE.

ISSN:0092-7872    

DOI:10.1080/00927879308824699

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1993

数据来源: Taylor

ISSN:0092-7872    

DOI:10.1080/00927879308824700

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1993

数据来源: Taylor

ISSN:0092-7872    

DOI:10.1080/00927879308824701

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1993

数据来源: Taylor

ISSN:0092-7872    

DOI:10.1080/00927879308824702

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1993

数据来源: Taylor

摘要:

Abstract. In this paper we show that there exists a spectral sequence withapproximatingthe Hochschild cohomology of crossed productsand that an isomorphismpreserves products. As an example, we determine the module structure of the Hochschild cohomology of a certain crossed product and also the ring structure in a special case.

ISSN:0092-7872    

DOI:10.1080/00927879308824703

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1993

数据来源: Taylor

摘要:

We establish relations between two extensions of Dickson's torsion theory, one introduced by Barr and the other by Cassidy, Hubert and Kelly. These two notions are studied in a general category and we show that categories with zero object are, in some sense, the ones where the second notion is relevant. In these categories, under suitable completeness conditions, we characterize torsion theories in terms of reflections and connections. A characterization of the torsion-free subcategories which generalizes the one of Dickson is also presented.

ISSN:0092-7872    

DOI:10.1080/00927879308824704

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1993

数据来源: Taylor

摘要:

The mod2 cohomology algebras of finite groups with dihedral Sylow 2-subgroups are completely determined, by using the theory of relatively projective covers.

ISSN:0092-7872    

DOI:10.1080/00927879308824705

出版商:Gordon and Breach Science Publishers Ltd.    

年代:1993

数据来源: Taylor