BIROn - Birkbeck Institutional Research Online

Complexity of equational theory of relational algebras with standard projection elements

Mikulás, Szabolcs and Sain, I. and Simon, A. (2015) Complexity of equational theory of relational algebras with standard projection elements. Synthese 192 (7), pp. 2159-2182. ISSN 0039-7857.

[img]
Preview
Text
mss-15.pdf - Author's Accepted Manuscript

Download (231kB) | Preview

Abstract

The class \(\mathsf{TPA}\) of t rue p airing a lgebras is defined to be the class of relation algebras expanded with concrete set theoretical projection functions. The main results of the present paper is that neither the equational theory of \(\mathsf{TPA}\) nor the first order theory of \(\mathsf{TPA}\) are decidable. Moreover, we show that the set of all equations valid in \(\mathsf{TPA}\) is exactly on the \(\Pi ^1_1\) level. We consider the class \(\mathsf{TPA}^-\) of the relation algebra reducts of \(\mathsf{TPA}\)’s, as well. We prove that the equational theory of \(\mathsf{TPA}^-\) is much simpler, namely, it is recursively enumerable. We also give motivation for our results and some connections to related work.

Metadata

Item Type: Article
Additional Information: The final publication is available at Springer via http://dx.doi.org/10.1007/s11229-015-0689-1
Keyword(s) / Subject(s): Logic, Algebraic logic, Finitization problem in algebraic logic, Recursion theory, Theoretical computer science
School: Birkbeck Faculties and Schools > Faculty of Science > School of Computing and Mathematical Sciences
Depositing User: Szabolcs Mikulas
Date Deposited: 10 Nov 2015 17:50
Last Modified: 23 Jul 2025 08:53
URI: https://eprints.bbk.ac.uk/id/eprint/13400

Statistics

6 month trend
516Downloads
6 month trend
307Hits

Additional statistics are available via IRStats2.

Archive Staff Only (login required)

Edit/View Item
Edit/View Item