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A preservation theorem for ec-structures with applications

Published online by Cambridge University Press:  12 March 2014

Michael H. Albert*
Affiliation:
Department of Pure Mathematics, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada

Abstract

We characterize the model companions of universal Horn classes generated by a two-element algebra (or ordered two-element algebra). We begin by proving that given two mutually model consistent classes M and N of (respectively ) structures, with , , provided that an -definability condition for the function and relation symbols of holds. We use this, together with Post's characterization of ISP(A), where A is a two-element algebra, to show that the model companions of these classes essentially lie in the classes of posets and semilattices, or characteristic two groups and relatively complemented distributive lattices.

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 1987

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References

REFERENCES

[1] Albert, M. H. and Burris, S., Finite axiomatisations for exponentially closed posets and semilattices, Order, vol. 3 (1986), pp. 169178.CrossRefGoogle Scholar
[2] Bacsich, P. and Hughes, D. Rowlands, Syntactic characterisations of amalgamation, convexity and related properties, this Journal, vol. 39 (1974), pp. 433451.Google Scholar
[3] Burris, S., Model companions for finitely generated universal Horn classes, this Journal, vol. 49 (1984), pp. 6874.Google Scholar
[4] Burris, S. and Werner, H., Sheaf constructions and their elementary properties, Transactions of the American Mathematical Society, vol. 248 (1979), pp. 267307.CrossRefGoogle Scholar
[5] Chang, C. C. and Keisler, H. J., Model theory, North-Holland, Amsterdam, 1973.Google Scholar
[6] Lyndon, R. C., Identities in two-valued calculi, Transactions of the American Mathematical Society, vol. 71 (1951), pp. 457465.CrossRefGoogle Scholar
[7] Macintyre, A., Model completeness, Handbook of mathematical logic (Barwise, J., editor), North-Holland, Amsterdam, 1977, pp. 139180.CrossRefGoogle Scholar
[8] Post, E., Two-valued iterative systems of mathematical logic, Princeton University Press, Princeton, New Jersey, 1941.Google Scholar