Hostname: page-component-8448b6f56d-qsmjn Total loading time: 0 Render date: 2024-04-24T09:51:09.287Z Has data issue: false hasContentIssue false

On generic extensions without the axiom of choice1

Published online by Cambridge University Press:  12 March 2014

G. P. Monro*
Affiliation:
University of Sydney, Sydney, NSW 2006, Australia

Abstract

Let ZF denote Zermelo-Fraenkel set theory (without the axiom of choice), and let M be a countable transitive model of ZF. The method of forcing extends M to another model M[G] of ZF (a “generic extension”). If the axiom of choice holds in M it also holds in M[G], that is, the axiom of choice is preserved by generic extensions. We show that this is not true for many weak forms of the axiom of choice, and we derive an application to Boolean toposes.

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 1983

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

1

While the work for this paper was done the author held a Fellowship at the University of Heidelberg from the Alexander von Humboldt Foundation of West Germany.

References

REFERENCES

[1]Bell, J. L., Boolean-valued models and independence proofs in set theory, Oxford Logic Guides, Oxford University Press, Oxford, 1977.Google Scholar
[2]Bell, J. L., Some aspects of the category of subobjects of constant objects in a topos, Journal of Pure and Applied Algebra (to appear).Google Scholar
[3]Felgner, Ulrich, Models of ZF-set theory, Lecture Notes in Mathematics, vol. 223, Springer-Verlag, Berlin, Heidelberg and New York, 1971.CrossRefGoogle Scholar
[4]Fourman, M. P. and Scott, D. S., Sheaves and logic, Applications of Sheaves: Proceedings of the Durham Conference 1977 (Fourman, M.P., Mulvey, C.J. and Scott, D.S., editors), Lecture Notes in Mathematics, vol. 753, Springer-Verlag, Berlin, Heidelberg and New York, 1979, pp. 302401.CrossRefGoogle Scholar
[5]Halpern, J. D. and Lévy, A.. The Boolean prime ideal theorem does not imply the axiom of of choice, Axiomatic Set Theory, Proceedings of Symposia in Pure Mathematics, vol. XIII, Part I (Scott, D.S., editor), American Mathematical Society, Providence, Rhode Island, 1971, pp. 83134.CrossRefGoogle Scholar
[6]Higgs, Denis, A category approach to Boolean-valued set theory, University of Waterloo, 1973 (preprint).Google Scholar
[7]Johnstone, P. T., Topos theory, L.M.S. Monographs, Academic Press, London, New York and San Francisco, 1977.Google Scholar
[8]Kinna, W. and Wagner, K., Über eine Abschwāchung des Auswahlpostulates, Fundamenta Mathematicae, vol. 42 (1955), pp. 7682.CrossRefGoogle Scholar
[9]Lévy, A., The independence of various definitions of finiteness, Fundamenta Mathematicae, vol. 46 (1958), pp. 113.CrossRefGoogle Scholar
[10]Lévy, A., The interdependence of certain consequences of the axiom of choice, Fundamenta Mathematicae, vol. 54 (1964), pp. 135157.CrossRefGoogle Scholar
[11]Lós, J. and Ryll-Nardzewski, C., On the application of Tychonoff's theorem in mathematical proofs, Fundamenta Mathematicae, vol. 38 (1951), pp. 233237.CrossRefGoogle Scholar
[12]Mathias, A. R. D., The order extension principle, Axiomatic Set Theory, Proceedings of Symposia in Pure Mathematics, vol. XIII, Part II (Jech, T.J., editor), American Mathematical Society, Providence, Rhode Island, 1974, pp. 179184.CrossRefGoogle Scholar
[13]Monro, G. P., The cardinal equation 2m = m, Colloquium Mathematicum, vol. 29 (1974), pp. 15.CrossRefGoogle Scholar
[14]Scott, D. S., Lectures on Boolean-valued models for set theory, unpublished lecture notes for the American Mathematical Society Summer Research Institute on Axiomatic Set Theory at the University of California, Los Angeles, 1967.Google Scholar
[15]Shoenfield, J. R., Unramified forcing, Axiomatic Set Theory, Proceedings of Symposia in Pure Mathematics, vol. XIII, Part I (Scott, D.S., editor), American Mathematical Society, Providence, Rhode Island, 1971, pp. 357381.CrossRefGoogle Scholar
[16]Whitehead, Alfred North and Russell, Bertrand, Principia Mathematica (3 vols.), 2nd edition, Cambridge University Press, Cambridge, 19251927.Google Scholar