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The complexity of the core model

Published online by Cambridge University Press:  12 March 2014

William J. Mitchell*
Affiliation:
Department of Mathematics, University of Florida, Gainesville, FL 32611., USA. E-mail:[email protected]

Abstract

If there is no inner model with a cardinal κ such that ο(κ) = κ++ then the set KHω1 is definable over Hω1 by a Δ4 formula, and the set of countable initial segments of the core model is definable over Hω1 by a Π3 formula. We show that if there is an inner model with infinitely many measurable cardinals then there is a model in which is not definable Σ3 by any Σ3 formula, and KHω1 is not definable by any boolean combination of Σ3 formulas.

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 1998

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References

REFERENCES

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