Hostname: page-component-84b7d79bbc-7nlkj Total loading time: 0 Render date: 2024-08-04T13:22:44.386Z Has data issue: false hasContentIssue false

Zermelo-Fraenkel consistency results by Fraenkel-Mostowski methods

Published online by Cambridge University Press:  12 March 2014

David Pincus*
Affiliation:
University of Washington, Seattle, Washington 98102

Extract

Fraenkel-Mostowski models are a particularly simple and conceptual tool for proving consistency results involving the axiom of choice, AC. These models satisfy the theory, FM, of a well founded universe of sets built from a ground set of individuals. Zermelo-Fraenkel set theory, ZF, is the extension of FM in which the set of individuals is assumed to be empty. In this paper we show that there is a large class of statements whose consistency with ZF can be proven directly by means of a Fraenkel-Mostowski model.

A statement, Φ, of set theory is said to be transferable if there is a metatheorem: If Φ is true in a Fraenkel-Mostowski model then Φ is consistent with ZF. Jech and Sochor introduced, in [12], the class of boundable statements and proved them to be transferable. Most existential contradictions of AC are boundable. It remains to find criteria under which Ψ ∧ Φ is transferable where Ψ is a universal consequence of AC and Φ is an existential contradiction of AC. To this end we give two classes of statements. Each class is closed under conjunction, contains the boundable statements, and contains a number of universal consequences of AC. Nearly every Fraenkel-Mostowski consistency in the literature falls into one of these two classes.

In §2 we give two generalizations of the boundable statements. In §§3 and 4 the classes of transferable statements are discussed. In §5 we discuss the transfer problem and prove a metatheorem concerning nontransferable statements.

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 1972

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.)

References

BIBLIOGRAPHY

[1]Bleicher, M. N., Some theorems on vector spaces and the axiom of choice, Fundamenta Mathematicae, vol. 54 (1963), pp. 95107.CrossRefGoogle Scholar
[2]Bleicher, M. N., Multiple choice axioms and the axiom of choice for finite sets, Fundamenta Mathematicae, vol. 57 (1965), pp. 247252.CrossRefGoogle Scholar
[3]Cohen, P. J., Set theory and the continuum hypothesis, Benjamin, New York, 1966.Google Scholar
[4]Easton, W. B., Powers of regular cardinals, Annals of Mathematical Logic, vol. 1 (1970), pp. 137178.CrossRefGoogle Scholar
[5]Ellentuck, E., The universal properties of Dedekind finite cardinals, Annals of Mathematics (2), vol. 82 (1965), pp. 225248.CrossRefGoogle Scholar
[6]Ellentuck, E., Generalized ‘idempotence in cardinal arithmetic,’ Fundamenta Mathematicae, vol. 58 (1966), pp. 241258.CrossRefGoogle Scholar
[7]Gauntt, R. J., Some restricted versions of the axiom of choice, Notices of the American Mathematical Society, vol. 15 (1968), p. 351. Abstract 68T-176.Google Scholar
[8]Gauntt, R. J., Axioms of choice for finite sets. A solution to a problem of Mostowski (to appear).Google Scholar
[9]Halpern, J. D., The independence of the axiom of choice from the Boolean prime ideal theorem, Fundamenta Mathematicae, vol. 55 (1964), pp. 5766.CrossRefGoogle Scholar
[10]Halpern, J. D. and Levy, A., The Boolean prime ideal theorem does not imply the axiom of choice, Proceedings of Symposia in Pure Mathematics, Vol. 13, Part 1, American Mathematical Society, Providence, R.I., 1971, pp. 83134.Google Scholar
[11]Jech, T., Interdependence of weakened forms of the axiom of choice, Commentationes Mathematicae Universitatis Carolinae, vol. 7 (1966), pp. 359371.Google Scholar
[12]Jech, T. and Sochor, A., Applications of the θ-model, Bulletin de l'Académie Polonaise des Sciences, vol. 14 (1966), pp. 351355.Google Scholar
[13]Lauchli, H., Auswahlaxiom in der Algebra, Commentarii Mathematici Helvetici, vol. 37 (1962/1963), pp. 118.CrossRefGoogle Scholar
[14]Lauchli, H., The independence of the ordering principle from a restricted axiom of choice, Fundamenta Mathematicae, vol. 54 (1964), pp. 3143.CrossRefGoogle Scholar
[15]Levy, A., The independence of various definitions of finiteness, Fundamenta Mathematicae, vol. 46 (1958), pp. 113.CrossRefGoogle Scholar
[16]Levy, A., Axioms of multiple choice, Fundamenta Mathematicae, vol. 50 (1962), pp. 475483.CrossRefGoogle Scholar
[17]Levy, A., Interdependence of certain consequences of the axiom of choice, Fundamenta Mathematicae, vol. 54 (1964), pp. 135157.CrossRefGoogle Scholar
[18]Marek, W., A remark on independence proofs, Bulletin de l'Académie Polonaise des Sciences, vol. 14 (1966), pp. 543545.Google Scholar
[19]Mostowski, A., Über die Unabhangigkeit des Auswahlaxioms von Ordnungsprinzip, Fundamenta Mathematicae, vol. 32 (1939), pp. 201252.CrossRefGoogle Scholar
[20]Mostowski, A., Axiom of choice for finite sets, Fundamenta Mathematicae, vol. 33 (1945), pp. 137168.CrossRefGoogle Scholar
[21]Mostowski, A., On the principle of dependent choices, Fundamenta Mathematicae, vol. 35 (1948), pp. 127130.CrossRefGoogle Scholar
[22]Pincus, D., Comparison of independence results in Mostowski's system (G) and in Zermelo-Fraenkel set theory, Notices of the American Mathematical Society, vol. 15 (1968), p. 234. Abstract 68T-142.Google Scholar
[23]Pincus, D., Individuals in Zermelo-Fraenkel set theory, Dissertation, Harvard University, Cambridge, Mass., 1969.Google Scholar
[24]Pincus, D., Support structures for the axiom of choice, this Journal, vol. 36 (1971), pp. 2839.Google Scholar
[25]Rubin, H. and Rubin, J., Equivalents to the axiom of choice, Studies in logic, North-Holland, Amsterdam, 1963.Google Scholar
[26]Scott, D., Definitions by abstraction in axiomatic set theory, Bulletin of the American Mathematical Society, vol. 61 (1955), p. 442.Google Scholar
[27]Zuckerman, M. M., On choosing subsets of n-element sets, Fundamenta Mathematicae, vol. 64 (1969), pp. 163179.CrossRefGoogle Scholar
[28]Zuckerman, M. M., Multiple choice axioms, Proceedings of Symposia in Pure Mathematics, Vol. 13, Part 1, American Mathematical Society, Providence, R.I., 1971, pp. 447466.Google Scholar
[29]Zuckerman, M. M., Choices from finite sets and choices of finite subsets, Proceedings of the American Mathematical Society, vol. 27 (1971), pp. 133138.CrossRefGoogle Scholar