Hostname: page-component-76fb5796d-zzh7m Total loading time: 0 Render date: 2024-04-26T15:26:56.877Z Has data issue: false hasContentIssue false

A new omitting types theorem for L(Q)

Published online by Cambridge University Press:  12 March 2014

Matt Kaufmann*
Affiliation:
Universtiy of Wisconsin, Madison, Wisconsin 53706 Purdue University, W. Lafayette, Indiana 47907

Extract

For L a countable first-order language, let L(Q) be logic with the quantifier Qx which means “there exist uncountably many x”. We assume a little familiarity with Keisler's paper [8]. One finds there completeness and compactness theorems for L(Q), as well as an omitting types theorem: a syntactic condition is given for a consistent countable theory to have a model satisfying ∀x⋁Σ(x), where Σ is a countable set of formulas of L(Q). (See also Chang and Keisler [3] for the first-order omitting types theorem, due to Henkin and Orey.) An analogous theorem is proved in Barwise, Kaufmann, and Makkai [1] and in Kaufmann [6] for stationary logic. However, a more general theorem than just an anlaogue to Keisler's is proved there. Conditions are given which are sufficient for a theory T to have models satisfying sentences such as aas1aas2aasn⋁Σ(s1, … sn), ∀xaas ∨ Σ(x, s), and so forth. Bruce [2] had asked whether such a theorem can be proved for L(Q). with “aa” replaced by “Q*”, where Q* is ¬Q¬ (“for all but countably many”).

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 1979

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]Barwise, J., Kaufmann, M. and Makkai, M., Stationary logic, Annals of Mathematical Logic, vol. 13 (1978), pp. 171224.CrossRefGoogle Scholar
[2]Bruce, K., Model-theoretic forcing in logic with a generalized quantifier, Annals of Mathematical Logic, vol. 13 (1978), pp. 225265.CrossRefGoogle Scholar
[3]Chang, C. C. and Keisler, H. J., Model theory, North-Holland, Amsterdam, 1973.Google Scholar
[4]Gaifman, H., Model and types of Peano's arithmetic, Annals of Mathematical Logic, vol. 9 (1976), pp. 223306.CrossRefGoogle Scholar
[5]Kaufmann, M., A new omitting types theorem for L(Q), Notices of the American Mathematical Society, vol. 24 (1977), p. A549.Google Scholar
[6]Kaufmann, M., Some results in stationary logic. Doctoral dissertation, University of Wisconsin at Madison, 1978.Google Scholar
[7]Kaufmann, M., Omitting types and L(Q), abstract of talk at 06, 1978 ASL meeting at Madison. Wisconsin, this Journal (to appear).Google Scholar
[8]Keisler, H. J., Logic with the quantifier “there exist uncountably many”, Annals of Mathematical Logic, vol. 1 (1970), pp. 193.CrossRefGoogle Scholar
[9]Magidor, M. and Malitz, J., Compact extensions of L(Q), Part la, Annals of Mathematical Logic, vol. 11 (1977), pp. 217261.CrossRefGoogle Scholar
[10]Wimmers, E., A different proof of “A new omitting types theorem for HQ)”, mimeograph, University of Wisconsin, Madison, 1978.Google Scholar