-категоричные коммутативные кольца
-groups and pseudo-bad groups.
-theories of Boolean algebras
-purity and orthogonality.
-свободные группы.
A characterization of Ext(G,ℤ) assuming (V = L)
We complete the characterization of Ext(G,ℤ) for any torsion-free abelian group G assuming Gödel’s axiom of constructibility plus there is no weakly compact cardinal. In particular, we prove in (V = L) that, for a singular cardinal ν of uncountable cofinality which is less than the first weakly compact cardinal and for every sequence of cardinals satisfying (where Π is the set of all primes), there is a torsion-free abelian group G of size ν such that equals the p-rank of Ext(G,ℤ) for every...
A failure of quantifier elimination.
We show that log is needed to eliminate quantifiers in the theory of the real numbers with restricted analytic functions and exponentiation.
A family of logarithmic functions of distinct growth rates
We construct a totally ordered set Γ of positive infinite germs (i.e. germs of positive real-valued functions that tend to +∞), with order type being the lexicographic product ℵ1 × ℤ2. We show that Γ admits order preserving automorphisms of pairwise distinct growth rates.
A group in a group.
A measure theoretic approach to logical quantification
A model-theoretic transfer theorem for henselian valued fields.
A note on Robinson's non-negativity criterion
A remark on Ax's theorem on solvability modulo primes.
A representation of models of Peano arithmetic
A splitting theorem for ℱ-products
Algebraic dimension over Frobenius fields.
Algebraically closed and existentially closed substructures in categorical context.
An elementary class extending abelian-by- groups, for infinite
We show that for no infinite group the class of abelian-by- groups is elementary, but, at least when is an infinite elementary abelian -group (with prime), the class of groups admitting a normal abelian subgroup whose quotient group is elementarily equivalent to is elementary.
An invariant for difference field extensions
In this paper we introduce a new invariant for extensions of difference fields, the distant degree, and discuss its properties.
Anelli regolari separabilmente chiusi