| Title: | On direct sums of $\Cal B^{(1)}$-groups (English) | 
| Author: | Metelli, Claudia | 
| Language: | English | 
| Journal: | Commentationes Mathematicae Universitatis Carolinae | 
| ISSN: | 0010-2628 (print) | 
| ISSN: | 1213-7243 (online) | 
| Volume: | 34 | 
| Issue: | 3 | 
| Year: | 1993 | 
| Pages: | 587-591 | 
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| Category: | math | 
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| Summary: | A necessary and sufficient condition is given for the direct sum of two $\Cal B^{(1)}$-groups to be (quasi-isomorphic to) a $\Cal B^{(1)}$-group. A $\Cal B^{(1)}$-group is a torsionfree Abelian group that can be realized as the quotient of a finite direct sum of rank 1 groups modulo a pure subgroup of rank 1. (English) | 
| Keyword: | $\Cal B^{(1)}$-groups | 
| Keyword: | Butler groups of finite rank | 
| MSC: | 20K15 | 
| MSC: | 20K25 | 
| idZBL: | Zbl 0787.20031 | 
| idMR: | MR1243091 | 
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| Date available: | 2009-01-08T18:06:37Z | 
| Last updated: | 2012-04-30 | 
| Stable URL: | http://hdl.handle.net/10338.dmlcz/118616 | 
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| Related article: | http://dml.cz/handle/10338.dmlcz/119586 | 
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| Reference: | [FM] Fuchs L., Metelli C.: On a class of Butler groups.Manuscripta Math 71 (1991), 1-28. Zbl 0765.20026, MR 1094735 | 
| Reference: | [B] Höfling B.: On direct summands of Butler $\Cal B^{(1)}$-groups.to appear in Comm. in Algebra. MR 1215549 | 
| Reference: | [F II] Fuchs L.: Infinite Abelian Groups.Vol. II, Academic Press, London-New York, 1973. Zbl 0338.20063, MR 0349869 | 
| Reference: | Albrecht U.F., Goeters H.P., Megibben C.: Zero-one matrices with an application to Abelian groups.to appear in Rend. Sem. Mat. Univ. Padova. Zbl 0809.20046, MR 1257128 | 
| Reference: | Goeters H.P., Megibben C.: Quasi-isomorphism and $\Bbb Z (2)$ representations for a class of Butler groups.preprint. MR 1876211 | 
| Reference: | Goeters H.P., Ullery W.: Butler groups and lattices of types.Comment. Math. Univ. Carolinae 31 (1990), 613-619. Zbl 0717.20039, MR 1091358 | 
| Reference: | Goeters H.P., Ullery W.: Quasi-summands of a certain class of Butler groups.to appear in Proceedings of the 1991 Curacao Conference. Zbl 0806.20043, MR 1217267 | 
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