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Some remarks on openly generated Boolean algebras

Published online by Cambridge University Press:  12 March 2014

Sakaé Fuchino*
Affiliation:
Institut für Mathematik II, Freie Universität Berlin, W-1000 Berlin 33, Federal Republic of Germany E-mail: fuchino@math.fu-berlin.de

Abstract

A Boolean algebra B is said to be openly generated if {A : ArcB, ∣A∣ = ℵ0} includes a club subset of . We show:

(V = L). For any cardinal κ there exists an Lκ-free Boolean algebra which is not openly generated (Proposition 4.1).

(MA+(σ-closed)). Every -free Boolean algebra is openly generated (Theorem 4.2).

The last assertion follows from a characterization of openly generated Boolean algebras under MA+(σ-closed) (Theorem 3.1). Using this characterization we also prove the independence of problem 7 in Ščepin [15] (Proposition 4.3 and Theorem 4.4).

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 1994

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References

REFERENCES

[1] Bandlow, I., Factorization theorems and ‘strong’ sequences in bicompacta, Soviet Mathematics Doklady, vol. 22 (1980), pp. 196200.Google Scholar
[2] Barwise, J. and Feferman, S. (Editors), Model-theoretic logics, Springer-Verlag, New York, Heidelberg, Berlin, 1985.Google Scholar
[3] Baumgartner, J. E., Applications of the proper forcing axiom, Handbook of set theoretic topology (Kunen, K. and Vaughan, J. E., editors), North-Holland, Amsterdam, New York, Oxford, 1984.Google Scholar
[4] Eklov, P. C., Applications to algebra, Model-theoretic logics (Barwise, J. and Feferman, S., editors), Springer-Verlag, New York, Heidelberg, Berlin, 1985, pp. 423441.Google Scholar
[5] Feng, Q. and Jech, T., Local clubs, reflection, and preserving stationary sets, Proceedings of the London Mathematical Society, vol. 58 (1989), pp. 237257.CrossRefGoogle Scholar
[6] Foreman, M., Magidor, M., and Shelah, S., Martin's maximum, saturated ideals, and nonregular ultrafilters. part I, Annals of Mathematics, vol. 127 (1988).Google Scholar
[7] Fuchino, S., Potential embedding and versions of Martin's axiom, Notre Dame Journal of Symbolic Logic, vol. 33 (1992), pp. 481492.Google Scholar
[8] Fuchino, S., Some problems of Ščepin on openly generated Boolean algebras, Proceedings of the 10th Easter Conference, Humboldt Universität, Berlin, 1993 (to appear).Google Scholar
[9] Fuchino, S., Koppelberg, S., and Takahashi, M., On L κ-free Boolean algebras, Annals of Pure and Applied Logic, vol. 55 (1992), pp. 265284.CrossRefGoogle Scholar
[10] Heindorf, L., Openly generated Boolean algebras, mimeograph dated on 10 9, 1992.Google Scholar
[11] Jech, J., Multiple forcing, Cambridge University Press, London and New York, 1987.CrossRefGoogle Scholar
[12] Koppelberg, S., General theory of Boolean algebras, Handbook of Boolean Algebras, vol. 1 (Monk, J. D. and Bonnet, R., editors), North-Holland, Amsterdam, New York, Oxford, Tokyo, 1989.Google Scholar
[13] Koppelberg, S., Projective Boolean algebras, Handbook of Boolean Algebras, vol. 3 (Monk, J. D. with Bonnet, R., editors), North-Holland, Amsterdam, New York, Oxford, Tokyo, 1989, pp. 741773.Google Scholar
[14] Kueker, D., -elementarily equivalent models of power ω1, Logic year 1979–80, Lecture Notes in Mathematics, vol. 859, Springer-Verlag, Berlin and New York, 1981, pp. 120131.CrossRefGoogle Scholar
[15] Ščepin, E. V., Functors and uncountable powers of compacta, Uspechi Matematicheskikh Nauk, vol. 36 (1981), pp. 362; English translation, Russian Mathematical Suveys, vol. 36 (1981), pp. 171.Google Scholar
[16] Shelah, S., Semiproper forcing axiom implies Martin's maximum but not PFA+, this Journal, vol. 52 (1987), pp. 360367.Google Scholar