Profinite Structures are Retracts of Ultraproducts of Finite Structures

• Autorzy: Mariano H. L. , Miraglia F.
• Języki publikacji: EN

Abstrakty

EN

We show that if L is a rst-order language with equality, then pronite L-structures, the projective limits of finite L-structures, are retracts of certain ultraproducts of finite L-structures. As a consequence, any elementary class of L-structures axiomatized by L-sentences of the form for all x( 0(~x) -- 1(~x)), where 0(~x); 1(~x) are positive existential L-formulas, is closed under the formation of pronite objects in L-mod, the category of Lstructures and L-homomorphisms. We also mention some interesting applications of our main result to the Theory of Special Groups that have already appeared in the literature.

• Wydawca: Wydawnictwo Uniwersytetu Jagiellońskiego
• Czasopismo: Reports on Mathematical Logic
• Rocznik: 2007
• Tom: No. 42
• Strony: 169--182
• Opis fizyczny: Bibliogr. 14 poz., rys.

Twórcy

autor

Mariano H. L.

autor

Miraglia F.

• Institute of Mathematics and Statistics, University of Sao Paulo, Sao Paulo, Brazil,

Bibliografia

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