Summary
We improve a theorem of Raisonnier by showing that Cons(ZFC+every Σ 12 -set of reals in Lebesgue measurable+every Π 12 -set of reals isK σ-regular) implies Cons(ZFC+there exists an inaccessible cardinal). We construct, fromL, a model where every Δ 13 -sets of reals is Lebesgue measurable, has the property of Baire, and every Σ 12 -set of reals isK σ-regular. We prove that if there exists a Σ 1 n+1 unbounded filter on ω, then there exists a nonK σ-regular Π 12 -subset.
Similar content being viewed by others
References
[Ba] Baumgartner, J.: Interated forcing. In: Surveys in set theory. Mathias, A.R.D. (ed.) Lond. Math. Soc. Lect. Notes Ser.8, 1–59 (1983) Cambridge University Press, Cambridge
[El] Ellentuck, E.: A new proof that analytic sets are Ramsey. J. Symb. Logic39, 163–165 (1974)
[HS] Harrington, L., Shelah, S.: Some exact equiconsistency results in set theory. Notre Dame J. Formal Logic26, 178–188 (1985)
[Ih] Judah, H.: 112-1 of reals. J. Symb. Logic53, 636–642 (1988)
[JS1] Judah, H., Shelah, S.: Martin's axioms, measurability and equiconsistency results. J. Symb. Logic54, 78–94 (1989)
[JS2] Judah, H., Shelah, S.: Souslin forcing. J. Symb. Logic53, 1188–1207 (1988)
[Je] Jech, T.: Set Theory. New York: Academic Press 1978
[Ke] Kechris, A.: On a notion of smallness for subsets of the Baire space. Trans. Am. Math. Soc.229, 191–207 (1977)
[MS] Martin, D., Solovay, R.: Internal Cohen extensions. Ann. Math. Logic2, 143–178 (1970)
[Ma] Mathias, A.R.D.: Happy families. Ann. Math. Logic12, 59–111 (1977)
[Ox] Oxtoby, J.: Measure and category. Berlin Heidelberg New York: Springer 1971
[Ra] Raisonnier, J.: A mathematical proof of S. Shelah's theorem on the measure problem and related result. Isr. J. Math.48, 48–56 (1984)
[RS] Raisonnier, J., Stern, J.: The strength of measurability hypotheses. Isr. J. Math.50, 337–349 (1985)
[Sh] Shelah, S.: Can you take Solovay's inaccessible away? Isr. J. Math.48, 1–47 (1984)
[So] Solovay, R.M.: A model of set theory in which every set of reals is Lebesgue mesurable. Ann. Math. Ser. (2)92, 1–56 (1970)
[St] Stern, J.: Regularity properties of definable sets of reals. Ann. Pure Appl. Logic29, 289–324 (1985)
Author information
Authors and Affiliations
Additional information
The author would like to thank the Basic Research Foundation (Israel Academy of Science) for partially supporting this research
Rights and permissions
About this article
Cite this article
Judah, H. Exact equiconsistency results for Δ 13 -sets of reals. Arch Math Logic 32, 101–112 (1992). https://doi.org/10.1007/BF01269952
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF01269952