Abstract
In this paper, we examine topological spaces that can be effectively defined over factor sets modulo equivalences on the set of natural numbers. We formulate a criterion of computable (effective) separability of topological spaces in terms of the approximability of the corresponding algebras by negative (uniformly effectively separated) algebras. We compare negative and positive algebra representations from the standpoint of the structure of the corresponding effective spaces. For effective infinite topological spaces, we prove the existence of their infinite effective compact extensions.
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References
Yu. L. Ershov, Numeration Theory [in Russian], Nauka, Moscow (1977).
Yu. L. Ershov, Solvability Problems and Constructive Models [in Russian], Nauka, Moscow (1980).
S. S. Goncharov and Yu. L. Ershov, Constructive Models [in Russian], Nauchnaya Kniga, Novosibirsk (1999).
N. Kh. Kasymov, “Algebras with finitely approximable, positively representable enrichments,” Algebra Logika, 26, No. 6, 715–730 (1987).
N. Kh. Kasymov, “Positive algebras with congruences of finite index,” Algebra Logika, 30, No. 3, 293–305 (1991).
N. Kh. Kasymov, “Positive algebras with countable congruence lattices,” Algebra Logika, 31, No. 1, 21–37 (1992).
N. Kh. Kasymov, “Homomorphisms onto negative algebras,” Algebra Logika, 31, No. 2, 132–144 (1992).
N. Kh. Kasymov, “The number of algebras over simple sets,” Mat. Zametki, 52, No. 2, 150–152 (1992).
N. Kh. Kasymov, “Separation axioms and partitions of the set of natural numbers,” Sib. Mat. Zh., 34, No. 3, 81–85 (1993).
N. Kh. Kasymov, “Enumerated algebras with uniformly recursive-separable classes,” Sib. Mat. Zh., 34, No. 5, 85–102 (1993).
N. Kh. Kasymov, “Algebras over negative equivalences,” Algebra Logika, 33, No. 1, 76–80 (1994).
N. Kh. Kasymov, “Recursively separable enumerated algebras,” Usp. Mat. Nauk, 51, No. 3 (309), 145–176 (1996).
N. Kh. Kasymov, “Homomorphisms onto effectively separable algebras,” Sib. Mat. Zh., 57, No. 1, 47–66 (2016).
A. I. Mal’tsev, “Constructive algebras, I,” Usp. Mat. Nauk, 16, No. 3 (99), 3–60 (1961).
A. I. Mal’tsev, Algorithms and Recursive Functions [in Russian], Nauka, Moscow (1986).
V. A. Uspensky, “On computable operations,” Dokl. Akad. Nauk SSSR, 103, No. 5, 773–776 (1955).
V. A. Uspensky, “Systems of encountable sets and their numeratrions,” Dokl. Akad. Nauk SSSR, 105, No. 6, 1155–1158 (1955).
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Dedicated to the memory of Academician T. N. Kary-Niyazov
Translated from Itogi Nauki i Tekhniki, Seriya Sovremennaya Matematika i Ee Prilozheniya. Tematicheskie Obzory, Vol. 144, Proceedings of the Conference “Problems of Modern Topology and Its Applications” (May 11–12, 2017), Tashkent, Uzbekistan, 2018.
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Kasymov, N.K., Khodzhamuratova, I.A. Topological Spaces Over Algorithmic Representations of Universal Algebras. J Math Sci 245, 311–322 (2020). https://doi.org/10.1007/s10958-020-04692-6
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DOI: https://doi.org/10.1007/s10958-020-04692-6