Abstract
If the language is extended by new individual variables, in classical first order logic, then the deduction system obtained is a conservative extension of the original one. This fails to be true for the logics with infinitary predicates. But it is shown that restricting the commutativity of quantifiers and the equality axioms in the extended system and supposing the merry-go-round property in the original system, the foregoing extension is already conservative. It is shown that these restrictions are crucial for an extension to be conservative. The origin of the results is algebraic logic.
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References
Andréka H., Thompson R.J.: ‘A Stone type representation theorem for algebras of relations of higher rank’. Transaction of Amer. Math. Soc. 309, 671–682 (1988)
Ferenczi M.: ‘On representability of neatly embeddable cylindric algebras’. Journal of Applied and Non-Classical Logics 3–4, 300–315 (2000)
Ferenczi M., Sági G.: ‘On some developments in the representation theory of cylindric-like algebras’. Algebra Universalis 55, 345–353 (2006)
Johnson J.S.: ‘Axiom system for first order logic with finitely many variables’. Journal of Symbolic Logic 38, 576–578 (1973)
Henkin, L., J.D. Monk, and A. Tarski, Cylindric Algebras I., North Holland, 1971.
Henkin, L., J. D. Monk, and A. Tarski, Cylindric Algebras II, North Holland, 1985.
Hirsch R., Hodkinson I., Maddux R.: ‘Provability with finitely many variables’. Bulletin of Symbolic Logic 8, 348–379 (2002)
Keisler H.J.: ‘A complete first order logic with infinitary predicates’. Fund. Math. 52, 177–203 (1963)
Monk J.D.: ‘Provability with finitely many variables’. Proc. Amer. Math. Soc. 27, 353–358 (1971)
Monk, J.D., Mathematical Logic, Springer, 1976.
Salibra, A., ‘A general theory of algebras with quantifiers, in Algebraic Logic’, ed. Andréka, H., Monk, J.D., Németi, I., Colloq. Math. Soc. J. Bolyai, 54, North Holland, 573–621, 1991.
Sayed Ahmed Tarek, and B. Samir, ‘A neat embedding theorem for expansions of cylindric algebras’, Log. J. of IGPL 15:41–57, 2007.
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Ferenczi, M. On Conservative Extensions in Logics with Infinitary Predicates. Stud Logica 92, 121–135 (2009). https://doi.org/10.1007/s11225-009-9189-y
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DOI: https://doi.org/10.1007/s11225-009-9189-y