On a class of locally Butler groups
Bican, Ladislav
Commentationes Mathematicae Universitatis Carolinae, Tome 32 (1991), p. 597-600 / Harvested from Czech Digital Mathematics Library
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A torsionfree abelian group $B$ is called a Butler group if $Bext(B,T) = 0$ for any torsion group $T$. It has been shown in [DHR] that under $CH$ any countable pure subgroup of a Butler group of cardinality not exceeding $\aleph_\omega$ is again Butler. The purpose of this note is to show that this property has any Butler group which can be expressed as a smooth union $\cup_{\alpha < \mu}B_\alpha$ of pure subgroups $B_\alpha$ having countable typesets.

Publié le : 1991-01-01
Classification:  20K20,  20K27,  20K35 
@article{118438,
     author = {Ladislav Bican},
     title = {On a class of locally Butler groups},
     journal = {Commentationes Mathematicae Universitatis Carolinae},
     volume = {32},
     year = {1991},
     pages = {597-600},
     zbl = {0748.20029},
     mrnumber = {1159805},
     language = {en},
     url = {http://dml.mathdoc.fr/item/118438}
}

Bican, Ladislav. On a class of locally Butler groups. Commentationes Mathematicae Universitatis Carolinae, Tome 32 (1991) pp. 597-600. http://gdmltest.u-ga.fr/item/118438/

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