Hostname: page-component-76fb5796d-vfjqv Total loading time: 0 Render date: 2024-04-29T21:20:31.103Z Has data issue: false hasContentIssue false

Compactness and transfer for a fragment of L2

Published online by Cambridge University Press:  12 March 2014

M. Magidor
Affiliation:
University of Colorado, Boulder, Colorado 80302
J. Malitz
Affiliation:
University of Colorado, Boulder, Colorado 80302

Extract

The language Ln is obtained from the first order predicate calculus by adjoining the quantifier Qn which binds n variables. The formula Qnυ1 … υnΨ is given a κ-interpretation for each infinite cardinal κ, namely, “there is a set X of power κ such that Ψx1xn holds for all distinct x1xn ϵ X”. L is the result of adjoining all the Qn quantifiers for each n ϵ ω to the first order predicate calculus.

In [4] we showed that under the assumption (cf. [3]) L is countably compact under the ω1-interpretation, and that any sentence σ ϵ L that has a model in some κ-interpretation where κ is a regular infinite cardinal has a model in the ω1 interpretation. However, compactness for L in the κ-interpretation for κ an infinite successor cardinal other than ω1 and the transfer of satisfiability from ω1 to any higher power remain open questions under any set theoretic assumptions.

Here we restrict our attention to a small fragment L2− of L2 consisting of universal first order formulas along with formulas of the kind Q2υ1υ2∀υ3 … υnΨ and ¬Q2υ1υ2∀υ3 … υnφ where Ψ and φ are open and no function symbol of arity > 1 occurs in any formula. Assuming the existence of a κ-Souslin tree, this language is λ compact in the κ-interpretation when λ < κ.

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 1977

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]Jech, T., Nonprovability of Souslin's hypotheses, Commentationes Mathematicae Universitatis Carolinae, vol. 8 (1967), pp. 291305.Google Scholar
[2]Jensen, R. B., Souslin's hypothesis is incompatible with V = L, this Journal (to appear).Google Scholar
[3]Jensen, R. B., The fine structure of the constructive universe, Annals of Mathematical Logic, vol. 4 (1972), pp. 229308.CrossRefGoogle Scholar
[4]Magidor, M. and Malitz, J., Compact extensions of L(Q), Part la, Annals of Mathematical Logic (to appear).Google Scholar
[5]Tennenbaum, S., Souslin's problems, Proceedings of the National Academy of Sciences, vol. 59 (1968), pp. 6063.Google Scholar