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Ultraproducts of finite sets

Published online by Cambridge University Press:  12 March 2014

H. Jerome Keisler*
Affiliation:
University of Wisconsin

Extract

It is shown in [1] that an ultraproduct of finite sets can be of arbitrarily large cardinality, but if it is infinite then it must have at least the power of the continuum. In this paper we shall take a closer look at the cardinality of ultraproducts of finite sets. Our results were announced without proof in [5]. A discussion of the cardinality of ultraproducts of infinite sets, and another theorem about ultraproducts of finite sets, can be found in [3].

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 1967

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References

[I]Frayne, T., Morel, A. C. and Scott, D., Reduced direct products. Fundamenta Mathematicae, vol. 51 (1962), pp. 195228.CrossRefGoogle Scholar
[2]Keisler, H. J., Ultraproducts and saturated models, Indagationes Mathematicae, vol. 26 (1964), pp. 178186.CrossRefGoogle Scholar
[3]Keisler, H. J., On cardinalities of ultraproducts, Bulletin of the American Mathematical Society, vol. 70 (1964), pp. 644647.CrossRefGoogle Scholar
[4]Keisler, H. J., Good ideals in fields of sets, Annals of Mathematics, vol. 79 (1964), pp. 338359.CrossRefGoogle Scholar
[5]Keisler, H. J., A survey of ultraproducts, Logic, methodology and the philosophy of science, Proceedings of the 1964 International Congress, pp. 112126, Jerusalem, 1965.Google Scholar
[6]Keisler, H. J., Limit ultrapowers, Transactions of the American Mathematical Society, vol. 107 (1963), pp. 382408.CrossRefGoogle Scholar
[7]Kochen, S., Ultraproducts in the theory of models, Annals of Mathematics, vol. 74 (1961), pp. 221261.CrossRefGoogle Scholar
[8]Macdowell, K. and Specker, E., Modelle der Arithmetic, Infinitistic methods, Warsaw, 1961, pp. 257263.Google Scholar
[9]Morley, M. and Vaught, R., Homogeneous universal models, Mathematica Scandinavica, vol. 11 (1962), pp. 3757.CrossRefGoogle Scholar
[10]Tarski, A. and Vauoht, R., Arithmetical extensions of relational systems, Compositio Mathematica, vol. 13 (1957), pp. 81102.Google Scholar
[11]Gaifman, H., Uniform extension operators for models and their applications, Technical Report No. 21, U.S. Office of Naval Research, Information Systems Branch, Jerusalem, 1965.Google Scholar