Abstract
We introduce the notion of effective Axiom A and use it to show that some popular tree forcings are Suslin+. We introduce transitive nep and present a simplified version of Shelah’s “preserving a little implies preserving much”: If I is a Suslin ccc ideal (e.g. Lebesgue-null or meager) and P is a transitive nep forcing (e.g. P is Suslin+) and P does not make any I-positive Borel set small, then P does not make any I-positive set small.
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References
Bagaria J., Bosch R. (1997) Projective forcing. Ann. Pure Appl. Logic 86(3): 237–266
Bartoszyński T., Judah H. Set theory: on the structure of the real line. In: Peters A.K., (ed) Wellesley (1995)
Baumgartner J.E. (1983) Iterated forcing. In: Mathias A. (ed) Surveys in set theory, London mathematical society lecture note series, vol 87. Cambridge University Press, Cambridge, pp. 1–59
Goldstern M. Tools for your forcing construction. In: Judah H. (ed) Set Theory of The Reals, israel mathematical conference proceedings, vol. 6, pp. 305–360. American Mathematical Society (1993)
Goldstern M., Judah H. (1992) Iteration of Souslin forcing, projective measurability and the Borel conjecture. Isr. J. Math. 78, 335–362
Ihoda (Haim Judah), J., Shelah S. Souslin forcing. J. Symb. Logic 53, 1188–1207 (1988)
Judah H., Shelah S. (1990) The kunen-miller chart (lebesgue measure, the baire property, laver reals and preservation theorems for forcing). J. Symb. Logic 55, 909–927
Keisler H.J. (1970) Logic with the quantifier “there exist uncountably many”. Ann. Math. Logic 1, 1–93
Kellner J., Shelah S. Preserving preservation. J. Symb. Logic 70(3), 914–945 (2005). Math. LO/0405081
Pawlikowski J. Laver’s forcing and outer measure. In: Bartoszyński T., Scheepers M. (eds.) Proceedings of BEST conferences 1991–1994. American Mathematical Society, Providence (1995)
Roslanowski A., Shelah S. Norms on possibilities i: forcing with trees and creatures. Memoirs of the American Mathematical Society, vol. 141, xii + 167 (1999). Math.LO/9807172
Shelah S. (1998) Proper and improper forcing Perspectives in Mathematical Logic. Springer, Berlin Heidelberg New York
Shelah S. Properness without elementaricity. J. Appl. Anal. 10, 168–289 (2004). Math. LO/9712283
Sikorski R. (1964) Boolean Algebras. Springer, Berlin Heidelberg New York
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Kellner, J. Preserving Non-null with Suslin+ Forcings. Arch. Math. Logic 45, 649–664 (2006). https://doi.org/10.1007/s00153-006-0008-0
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DOI: https://doi.org/10.1007/s00153-006-0008-0