Hostname: page-component-8448b6f56d-c4f8m Total loading time: 0 Render date: 2024-04-16T10:27:26.628Z Has data issue: false hasContentIssue false

The dense linear ordering principle

Published online by Cambridge University Press:  12 March 2014

David Pincus*
Affiliation:
Departments of Anesthesia, Harvard Medical School, Massachusetts General Hospital, Cambridge Hospital, 1493 Cambridge Street, Cambridge, MA 02139, USA, E-mail: pincus@helix.mgh.harvard.edu

Abstract

Let DO denote the principle: Every infinite set has a dense linear ordering. DO is compared to other ordering principles such as O, the Linear Ordering principle, KW, the Kinna-Wagner Principle, and PI, the Prime Ideal Theorem, in ZF, Zermelo-Fraenkel set theory without AC, the Axiom of Choice.

The main result is:

Theorem. AC ⇒ KW ⇒ DO ⇒ O, and none of the implications is reversible in ZF + PI.

The first and third implications and their irreversibilities were known. The middle one is new. Along the way other results of interest are established. O, while not quite implying DO, does imply that every set differs finitely from a densely ordered set. The independence result for ZF is reduced to one for Fraenkel-Mostowski models by showing that DO falls into two of the known classes of statements automatically transferable from Fraenkel-Mostowski to ZF models. Finally, the proof of PI in the Fraenkel-Mostowski model leads naturally to versions of the Ramsey and Ehrenfeucht-Mostowski theorems involving sets that are both ordered and colored.

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 1997

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

REFERENCES

[1]Cohen, Paul J., The independence of the axiom of choice, Unpublished manuscript circulated summer 1963.Google Scholar
[2]Foreman, Matthew and Wehrung, Friedrich, The Hahn-Banach theorem implies the existence of a non-Lebesgue measurable set, Fundamenta Mathematicae, vol. 138 (1991), pp. 1319.CrossRefGoogle Scholar
[3]Gonzalez, Carlos G., Dense orderings, partitions, and weak forms of choice, to appear in Fundamenta Mathematicae.Google Scholar
[4]Gonzalez, Carlos G., Partitioning an infinite set, preprint circulated in 1994.Google Scholar
[5]Halpern, James D., The independence of the axiom of choice from the Boolean prime ideal theorem, Fundamenta Mathematicae, vol. 55 (1964), pp. 5766.CrossRefGoogle Scholar
[6]Halpern, James D. and Lauchli, Hans, A partition theorem, Transactions of the American Mathematical Society, vol. 124 (1966), pp. 360367.CrossRefGoogle Scholar
[7]Halpern, James D. and Levy, Azriel, The Boolean prime ideal theorem does not imply the axiom of choice, Axiomatic set theory (Scott, Dana S., editor), vol. 13, American Mathematical Society, Providence, 1971, Proceedings of Symposia in Pure Mathematics, part 1, pp. 83134.CrossRefGoogle Scholar
[8]Howard, Paul E. and Rubin, Jean E., Two models for the Boolean prime ideal theorem, preprint circulated in 10 1994.Google Scholar
[9]Jech, Thomas J., The axiom of choice, Studies in Logic and the Foundations of Mathematics, vol. 75, North-Holland Publishing Company, New York, 1973.Google Scholar
[10]Jech, Thomas J. and Sochor, Antonin, Applications of the θ-model, Bulletin de l'Académie Polonaise des Sciences, Série des Sciences Mathématiques, Astronomiques et Physiques, vol. 14 (1996), pp. 351355.Google Scholar
[11]Kinna, W. and Wagner, K., Über eine Abschwächung des Auswahlpostulates, Fundamenta Mathematicae, vol. 42 (1955), pp. 7582.CrossRefGoogle Scholar
[12]Mathias, Adrian R. D., The order extension principle, Axiomatic set theory (Jech, Thomas J., editor), vol. 13, American Mathematical Society, Providence, 1974, Proceedings of Symposia in Pure Mathematics, part 2, pp. 179183.CrossRefGoogle Scholar
[13]Mostowski, Andrzej M., Über die Unabhängigkeit des Wohlordnungssatzes von Ordnungsprinzip, Fundamenta Mathematicae, vol. 32 (1939), pp. 201252.CrossRefGoogle Scholar
[14]Pincus, David, Zermelo Fraenkel consistencies by Fraenkel-Mostowski methods, this Journal, vol. 37 (1972), pp. 721743.Google Scholar
[15]Pincus, David, On the independence of the Kinna Wagner principle, Zeitschrift für Mathematische Logik und Grundlagen der Mathematik, vol. 20 (1974), pp. 503516.CrossRefGoogle Scholar
[16]Pincus, David, Two model theoretic ideas in independence proofs, Fundamenta Mathematicae, vol. 92 (1976), pp. 113130.CrossRefGoogle Scholar
[17]Pincus, David, Adding dependent choice, Annals of Mathematical Logic, vol. 11 (1977), pp. 105144.CrossRefGoogle Scholar
[18]Pincus, David, Adding dependent choice to the prime ideal theorem, Logic colloquium '76 (Gandy, Robin O. and Hyland, J. Martin, editors), Studies in Logic and Foundations of Mathematics, vol. 87, North-Holland, Amsterdam, 1977, pp. 547565.Google Scholar
[19]Sageev, Gershon, An independence result concerning the axiom of choice, Annals of Mathematical Logic, vol. 8 (1975), pp. 1184.CrossRefGoogle Scholar
[20]Scott, Dana S., Prime ideal theorems for rings, lattices, and Boolean algebras, Bulletin of the American Mathematical Society, vol. 60 (1954), p. 390.Google Scholar