Infinitary axiomatizability of slender and cotorsion-free groups
نویسندگان
چکیده
منابع مشابه
Cotorsion theories cogenerated by א1-free abelian groups
Given an א1-free abelian group G we characterize the class CG of all torsion abelian groups T satisfying Ext(G, T ) = 0 assuming the special continuum hypothesis CH. Moreover, in Gödel’s constructable universe we prove that this characterizes CG for arbitrary torsion-free abelian G. It follows that there exist some ugly א1-free abelian groups.
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ژورنال
عنوان ژورنال: Bulletin of the Belgian Mathematical Society - Simon Stevin
سال: 2000
ISSN: 1370-1444
DOI: 10.36045/bbms/1103055621