Abstract
Σ-definability in hereditarily finite superstructures over algebraic systems is studied. We prove the Σ-definability criterion, which is then used as a basis for establishing the reduction theorem for regular theories and for obtaining a characterization of simple theories. The idea of a nonstandard recursion theory is developed using subfields of the field of reals as an example. A partial algebraic description is given for a distributive upper semilattice of mΣ-degrees in hereditarily finite superstructures over models of simple theories.
Similar content being viewed by others
References
Yu. L. Ershov,Definability and Computability [in Russian], Nauch. Kniga, Novosibirsk (1996).
V. A. Rudnev, “The existence of an inseparable pair in the recursive theory of admissible sets,”Algebra Logika,27, No. 1, 48–56 (1988).
V. A. Rudnev, “A universal recursive function on admissible sets,”Algebra Logika,25, No. 4, 425–435 (1986).
C. C. Chang and H. J. Keisler,Model Theory, North-Holland, Amsterdam (1973).
R. Yu. Vaitsenavithcyus, “Computable enumerations of computable functionals onRL-admissible sets,”Math. Log. Its Appl., Vol. 5, Institute of Mathematics and Cybernetics of the Lith. S.S.R. Academy of Science, Vilnyus (1987), pp. 123–132.
A. I. Stukachev, “A uniformization theorem in hereditarily finite superstructures,” inVychislitel’nye Sistemy, Vol. 161, Institute of Mathematics, Novosibirsk (1998), pp. 3–14.
N. G. Khisamiev, “Strongly constructive models of decidable theories,”Izv. Akad. Nauk Kaz. S.S.R., Ser. Fiz.-Mat., No. 1, 83–84 (1974).
H. Rogers,Theory of Recursive Functions and Effective Computability, McGraw-Hill, New York (1967).
Yu. L. Ershov, Problems of Decidability and Constructive Models [in Russian], Nauka, Moscow (1980).
Additional information
Dedicated to the 60th birthday of Academician Yu. L. Ershov
Supported by RFFR grant No. 99-01-00600, and through FP “Integration” project 274.
Translated fromAlgebra i Logika, Vol. 39, No. 2, pp. 170–197, March–April, 2000.
Rights and permissions
About this article
Cite this article
Puzarenko, V.G. Computability over models of decidable theories. Algebr Logic 39, 98–113 (2000). https://doi.org/10.1007/BF02681664
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF02681664