Geodesic
Almost Butler groups
Czechoslovak Mathematical Journal, Tome 50 (2000) no. 2, pp. 367-378 Cet article a éte moissonné depuis la source Czech Digital Mathematics Library

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Generalizing the notion of the almost free group we introduce almost Butler groups. An almost $B_2$-group $G$ of singular cardinality is a $B_2$-group. Since almost $B_2$-groups have preseparative chains, the same result in regular cardinality holds under the additional hypothesis that $G$ is a $B_1$-group. Some other results characterizing $B_2$-groups within the classes of almost $B_1$-groups and almost $B_2$-groups are obtained. A theorem of stating that a group $G$ of weakly compact cardinality $\lambda $ having a $\lambda $-filtration consisting of pure $B_2$-subgroup is a $B_2$-group appears as a corollary.
Generalizing the notion of the almost free group we introduce almost Butler groups. An almost $B_2$-group $G$ of singular cardinality is a $B_2$-group. Since almost $B_2$-groups have preseparative chains, the same result in regular cardinality holds under the additional hypothesis that $G$ is a $B_1$-group. Some other results characterizing $B_2$-groups within the classes of almost $B_1$-groups and almost $B_2$-groups are obtained. A theorem of stating that a group $G$ of weakly compact cardinality $\lambda $ having a $\lambda $-filtration consisting of pure $B_2$-subgroup is a $B_2$-group appears as a corollary.
Classification : 20K20, 20K27 
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     author = {Bican, Ladislav},
     title = {Almost {Butler} groups},
     journal = {Czechoslovak Mathematical Journal},
     pages = {367--378},
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     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMJ_2000_50_2_a11/}
}
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Bican, Ladislav. Almost Butler groups. Czechoslovak Mathematical Journal, Tome 50 (2000) no. 2, pp. 367-378. http://geodesic.mathdoc.fr/item/CMJ_2000_50_2_a11/

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