Sums of countable primary groups
نویسندگان
چکیده
منابع مشابه
On Countable Extensions of Primary Abelian Groups
It is proved that if A is an abelian p-group with a pure subgroup G so that A/G is at most countable and G is either p-totally projective or p-summable, then A is either p-totally projective or p-summable as well. Moreover, if in addition G is nice in A, then G being either strongly p-totally projective or strongly p-summable implies that so is A. This generalizes a classical result of Wallace ...
متن کاملIsomorphisms of Sums of Countable Boolean Algebras
Denote by nA the sum of n copies of a Boolean algebra A. We prove that, for any countable Boolean algebra A, nA at mA with m > n implies nA a (n + \)A. In [2], W. Hanf constructed a Boolean algebra H isomorphic to the direct product H X H X H but not to H X H. This result of Hanf was strengthened by J. Ketonen in [4]: there exists even a countable Boolean algebra with this property. In [1], P. ...
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ژورنال
عنوان ژورنال: Proceedings of the American Mathematical Society
سال: 1966
ISSN: 0002-9939
DOI: 10.1090/s0002-9939-1966-0199259-8