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Amalgamation in relation algebras

Published online by Cambridge University Press:  12 March 2014

Maarten Marx*
Affiliation:
Department of Computing, Imperial College, 180 Queen's Gate, SW7 2BZ London, UK, E-mail: m.marx@doc.ic.ac.uk

Extract

We investigate amalgamation properties of relational type algebras. Besides purely algebraic interest, amalgamation in a class of algebras is important because it leads to interpolation results for the logic corresponding to that class (cf. [15]). The multi-modal logic corresponding to relational type algebras became known under the name of “arrow logic” (cf. [18, 17]), and has been studied rather extensively lately (cf. [10]). Our research was inspired by the following result of Andréka et al. [1].

Let K be a class of relational type algebras such that

(i) composition is associative,

(ii) K is a class of boolean algebras with operators, and

(iii) K contains the representable relation algebras RRA.

Then the equational theory of K is undecidable.

On the other hand, there are several classes of relational type algebras (e.g., NA, WA denned below) whose equational (even universal) theories are decidable (cf. [13]). Composition is not associative in these classes. Theorem 5 indicates that also with respect to amalgamation (a very weak form of) associativity forms a borderline. We first recall the relevant definitions.

Type
Research Article
Copyright
Copyright © Association for Symbolic Logic 1998

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References

REFERENCES

[1] Andréka, H., Kurucz, Á., Németi, I., Sain, I., and Simon, A., Decidable and undecidable modal logics with a binary modality, Journal of Logic, Language and Information, vol. 4 (1995), pp. 191206.Google Scholar
[2] Comer, S., Classes without the amalgamation property, Pacific Journal of Mathematics, vol. 28 (1969), pp. 309318.Google Scholar
[3] Henkin, L., Monk, J. D., and Tarski, A., Cylindric algebras, Parts I and II, North-Holland, 1971 and 1985.Google Scholar
[4] Kiss, E. W., Márki, L., Prőhle, P., and Tholen, W., Categorical algebraic properties: Compendium on amalgamation, congruence extension, epimorphisms, residual smallness and injectivity, Stadia Scientiarum Mathematicarum Hungarica, vol. 18 (1983).Google Scholar
[5] Madarász, J., Definability and epimorphisms in relation algebras, Mathematics Institute of Budapest, manuscript, 1996.Google Scholar
[6] Maddux, R., Topics in relation algebras, Ph.D. thesis, University of California, Berkeley, California, 1978.Google Scholar
[7] Maddux, R., Some varieties containing relation algebras, Transactions of the American Mathematical Society, vol. 272 (1982), pp. 501526.10.1090/S0002-9947-1982-0662049-7Google Scholar
[8] Maksimova, L., Amalgamation and interpolation in normal modal logics, Stadia Logica, vol. L (1991), no. 3/4, pp. 457471.Google Scholar
[9] Marx, M., Algebraic relativization and arrow logic, Ph.D. thesis, Institute for Logic, Language and Computation, University of Amsterdam, 1995, ILLC Dissertation Series 1995–3.Google Scholar
[10] Marx, M., Pólos, L., and Masuch, M. (editors), Arrow logic and multimodal logics, Studies in Logic, Language and Information, CSLI Publications, Stanford, 1996.Google Scholar
[11] McKenzie, R., The representation of relation algebras, Ph.D. thesis , University of Colorado, Boulder, 1966.Google Scholar
[12] Németi, I., Cylindric-relativised set algebras have strong amalgamation, this Journal, vol. 50 (1985), no. 3, pp. 689700.Google Scholar
[13] Németi, I., Decidability of relation algebras with weakened associativity, Proceedings of the American Mathematical Society, vol. 100 (1987), no. 2, pp. 340344.Google Scholar
[14] Németi, I. and Simon, A., Relation algebras from cylindric andpolyadic algebras, Logic Journal of the IGPL, vol. 5 (1997), no. 4, pp. 575588.10.1093/jigpal/5.4.575Google Scholar
[15] Pigozzi, D., Amalgamation, congruence extension and interpolation properties in algebras, Algebra Universalis, vol. 1 (1972), pp. 269349.Google Scholar
[16] Sain, I., Beth's and Craig's properties via epimorphisms and amalgamation in algebraic logic, Algebraic logic and universal algebra in computer science, vol. 425, 1990, pp. 209226.Google Scholar
[17] van Benthem, J., Language in action (Categories, lambdas and dynamic logic), Studies in Logic, vol. 130, North-Holland, 1991.Google Scholar
[18] Venema, Y., Many–dimensional modal logic, Ph.D. thesis , Institute for Logic, Language and Computation, Universiteit van Amsterdam, 1992.Google Scholar