Skip to main content
Log in

From Belnap-Dunn Four-Valued Logic to Six-Valued Logics of Evidence and Truth

  • Published:
Studia Logica Aims and scope Submit manuscript

Abstract

The main aim of this paper is to introduce the logics of evidence and truth \(LET_{K}^+\) and \(LET_{F}^+\) together with sound, complete, and decidable six-valued deterministic semantics for them. These logics extend the logics \(LET_{K}\) and \(LET_{F}^-\) with rules of propagation of classicality, which are inferences that express how the classicality operator \({\circ }\) is transmitted from less complex to more complex sentences, and vice-versa. The six-valued semantics here proposed extends the 4 values of Belnap-Dunn logic with 2 more values that intend to represent (positive and negative) reliable information. A six-valued non-deterministic semantics for \(LET_{K}\) is obtained by means of Nmatrices based on swap structures, and the six-valued semantics for \(LET_{K}^+\) is then obtained by imposing restrictions on the semantics of \(LET_{K}\). These restrictions correspond exactly to the rules of propagation of classicality that extend \(LET_{K}\). The logic \(LET_{F}^+\) is obtained as the implication-free fragment of \(LET_{K}^+\). We also show that the 6 values of \(LET_{K}^+\) and \(LET_{F}^+\) define a lattice structure that extends the lattice L4 defined by the Belnap-Dunn four-valued logic with the 2 additional values mentioned above, intuitively interpreted as positive and negative reliable information. Finally, we also show that \(LET_{K}^+\) is Blok-Pigozzi algebraizable and that its implication-free fragment \(LET_{F}^+\) coincides with the degree-preserving logic of the involutive Stone algebras.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

Data Availability Statement

Data sharing not applicable to this article as no datasets were generated or analysed during the current study.

References

  1. Alves, E. H., Lógica e inconsistência: um estudo dos cálculos\(C_n\), \(1 \le n \le \omega \) (Logic and inconsistency: A study of the calculi\(C_n\), \(1 \le n \le \omega \), in Portuguese) Masters thesis, FFLCH, State University of São Paulo, 1976.

  2. Antunes, H., W. Carnielli, A. Kapsner, and A. Rodrigues, Kripke-style models for logics of evidence and truth, Axioms 9(3), 2020. https://www.mdpi.com/2075-1680/9/3/100.

  3. Antunes, H., A. Rodrigues, W. Carnielli, and M.E. Coniglio, Valuation semantics for first-order logics of evidence and truth, Journal of Philosophical Logic 2022. https://doi.org/10.1007/s10992-022-09662-8.

    Article  Google Scholar 

  4. Avron, A., Non-deterministic semantics for logics with a consistency operator, International Journal of Approximate Reasoning 45(2):271–287, 2007.

    Article  Google Scholar 

  5. Avron, A., and I. Lev, Canonical propositional Gentzen-type systems, in Proceedings of the First International Joint Conference on Automated Reasoning (IJCAR’01), Springer, 2001, pp. 529–544.

  6. Avron, A., and I. Lev, Non-deterministic multiple-valued structures, Journal of Logic and Computation 15(3):241–261, 2005.

    Article  Google Scholar 

  7. Belnap, N. D., How a computer should think, in G. Ryle, (ed.), Contemporary Aspects of Philosophy, Oriel Press, 1977 (reprinted in H. Omori, and H. Wansing, (eds.), New Essays on Belnap-Dunn Logic, Springer, 2019, pp. 35–55).

  8. Belnap, N. D., A useful four-valued logic, in J.M. Dunn, and G. Epstein, (eds.), Modern uses of multiple valued logics, Springer, Dordrecht, 1977, pp. 5–37 (reprinted in H. Omori, and H. Wansing, (eds.), New Essays on Belnap-Dunn Logic, Springer, 2019, pp. 55–77).

  9. Blok, W. J., and D. Pigozzi, Algebraizable logics, vol. 77 of Memoirs of the American Mathematical Society, American Mathematical Society, Providence, RI, USA, 1989.

  10. Brady, R., Depth relevance of some paraconsistent logics, Studia Logica 43(1-2):63–73, 1984.

    Article  Google Scholar 

  11. Cantú, L. M., and M. Figallo, On the logic that preserves degrees of truth associated to involutive Stone algebras, Logic Journal of the IGPL 28(5):1000–1020, 2020.

    Article  Google Scholar 

  12. Cantú, L. M., and M. Figallo, Cut-free sequent-style systems for a logic associated to involutive Stone algebras, Journal of Logic and Computation 2022. https://doi.org/10.1093/logcom/exac061

    Article  Google Scholar 

  13. Carnielli, W., Many-valued logics and plausible reasoning, in Proceedings of the XX International Congress on Many-Valued Logics, University of Charlotte, USA, IEEE Computer Society, 1990, pp. 328–335.

  14. Carnielli, W., Possible-Translations Semantics for Paraconsistent Logics, in D. Batens, C. Mortensen, G. Priest, and J. P. Van Bendegem, (eds.), Frontiers of Paraconsistent Logic: Proceedings of the I World Congress on Paraconsistency, Baldock: Research Studies Press, King’s College Publications, 2000, pp. 149–163.

  15. Carnielli, W., and M. E. Coniglio, Splitting Logics, in S. Artemov, H. Barringer, A. Garcez, L. Lamb, and J. Woods, (eds.), We Will Show Them! Essays in Honour of Dov Gabbay, vol. 1, College Publications, 2005, pp. 389–414.

  16. Carnielli, W., and M. E. Coniglio, Paraconsistent Logic: Consistency, Contradiction and Negation, vol. 40 of Logic, Epistemology, and the Unity of Science, Springer, 2016.

  17. Carnielli, W., M. E. Coniglio, and J. Marcos, Logics of formal inconsistency, in D. Gabbay and F. Guenthner, (eds.), Handbook of Philosophical Logic, vol. 14, Springer-Verlag, Amsterdam, 2007, pp. 1–93.

  18. Carnielli, W., and J. Marcos, A taxonomy of C-systems, in W. Carnielli, M. E. Coniglio, and I.M. L. D’Ottaviano, (eds.), Paraconsistency: The Logical Way to the Inconsistent, Marcel Dekker, New York, 2002.

  19. Carnielli, W., and A. Rodrigues, On the philosophy and mathematics of the logics of formal inconsistency, in J.-Y. Beziau, M. Chakraborty, and S. Dutta, (eds.), New Directions in Paraconsistent Logic: 5th WCP, Kolkata, India, vol. 152 of Springer Proceedings in Mathematics & Statistics, Springer, India, 2015, pp. 57–88.

  20. Carnielli, W., and A. Rodrigues, An epistemic approach to paraconsistency: a logic of evidence and truth. Synthese 196:3789–3813, 2017. https://doi.org/10.1007/s11229-017-1621-7. URL https://rdcu.be/ctJRQ.

  21. Cignoli, R., and M. S. de Gallego, The lattice structure of some Łukasiewicz algebras, Algebra Universalis 13:315–328, 1981.

    Article  Google Scholar 

  22. Cignoli, R., and M. S. de Gallego, Dualities for some De Morgan algebras with operators and Łukasiewicz algebras, Journal of the Australian Mathematical Society (Series A) 34:377–393, 1983.

    Article  Google Scholar 

  23. Coniglio, M. E., A. Figallo-Orellano, and A. C. Golzio, Non-deterministic algebraization of logics by swap structures, Logic Journal of IGPL 28:1021–1059, 2018.

    Article  Google Scholar 

  24. Coniglio, M. E., and A. Rodrigues, On six-valued logics of evidence and truth expanding Belnap-Dunn four-valued logic. arXiv:2209.12337 [math.LO], 2022.

  25. Coniglio, M. E., and G. V. Toledo, Two Decision Procedures for da Costa’s \(C_n\) Logics Based on Restricted Nmatrix Semantics. Studia Logica 110(3):601–642, 2022.

  26. da Costa, N. C. A., Sistemas Formais Inconsistentes. Curitiba: Editora da UFPR (1993), 1963.

    Google Scholar 

  27. da Costa, N. C. A., On the theory of inconsistent formal systems, Notre Dame Journal of Formal Logic XV, 4(4):497–510, 1974.

    Google Scholar 

  28. Dunn, J. M., The Algebra of Intensional Logics, Ph.D. thesis, University of Pittsburgh, 1966 (published as vol. 2 in the Logic PhDs series, College Publications, London, 2019).

  29. Dunn, J. M., Intuitive semantics for first-degree entailments and ‘coupled trees’. Philosophical Studies 29:149–168, 1976 (reprinted in H. Omori, and H. Wansing, (eds.), New Essays on Belnap-Dunn Logic, Springer, 2019, pp. 21–34).

  30. Dunn, J. M., Information in computer science, in P. Adriaans, and J. van Benthem, (eds.), Philosophy of Information, vol. 8 of Handbook of the Philosophy of Science, Elsevier, 2008, pp. 581–608.

  31. Dunn, J. M., Two, three, four, infinity: The path to the four-valued logic and beyond, in H. Omori, and H.Wansing, (eds.), New Essays on Belnap-Dunn Logic, Springer, 2019, pp. 77–97.

  32. Fetzer, J., Information: Does it have to be true? Minds and Machines 14:223–229, 2004.

    Article  Google Scholar 

  33. Font, J. M., Abstract Algebraic Logic: An Introductory Textbook. College Publications, London, 2016.

    Google Scholar 

  34. Gomes, J., V. Greati, S. Marcelino, Marcos, and U. Rivieccio, On Logics of Perfect Paradefinite Algebras, in M. Ayala-Rincon, and E. Bonelli, (eds.), Proceedings of the 16th Logical and Semantic Frameworks with Applications (LSFA 2021), vol. 357 of Electronic Proceedings in Theoretical Computer Science, 2022, pp. 56–76.

  35. Hazen, A., and F. Pelletier, K3, Ł3, LP, RM3, A3, FDE, M: How to make many-valued logics work for you, in H. Omori, and H. Wansing, (eds.), New Essays on Belnap-Dunn Logic, Springer, 2019, pp. 155–190.

  36. Ivlev, Ju., Tablitznoe postrojenie propozicionalnoj modalnoj logiki (Truth-tables for systems of propositional modal logic, in Russian). Vest. Mosk. Univ., Seria Filosofia, 1973.

  37. Ivlev, Ju., A semantics for modal calculi, Bulletin of the Section of Logic 17(3/4):114–121, 1988.

    Google Scholar 

  38. Kearns, T., Modal semantics without possible worlds, The Journal of Symbolic Logic 46:77–86, 1981.

    Article  Google Scholar 

  39. Klein-Barmen, F., Grundzüge Der Theorie Der Verbände. Mathematische Annalen 111(1):596–621, 1935.

    Article  Google Scholar 

  40. Kramer, R. L., and R. D. Maddux, Relation algebras of Sugihara, Belnap, Meyer, and Church. Journal of Logical and Algebraic Methods in Programming 117, 2020, 100604. https://doi.org/10.1016/j.jlamp.2020.100604.

    Article  Google Scholar 

  41. Loparic, A., A semantical study of some propositional calculi, The Journal of Non-Classical Logic 3(1): 73–95, 1986.

    Google Scholar 

  42. Loparic, A., and E. Alves, The semantics of the systems \(Cn\) of da Costa, in A. Arruda, N. da Costa, and A. Sette, (eds.), Proceedings of the Third Brazilian Conference on Mathematical Logic, Sociedade Brasileira de Lógica, São Paulo, 1980, pp. 161–172.

  43. Loparic, A., and N. da Costa, Paraconsistency, paracompleteness and valuations. Logique et Analyse 106:119–131, 1984.

    Google Scholar 

  44. Marcelino, S., and U. Rivieccio, Logics of involutive Stone algebras, Soft Computing 26(7):3147–3160, 2022.

    Article  Google Scholar 

  45. Omori, H., and H. Wansing, 40 years of FDE: An introductory overview, Studia Logica 105:1021–1049, 2017.

    Article  Google Scholar 

  46. Pynko, A. P., Functional completeness and axiomatizability within Belnap’s four-valued logic and its expansions, Journal of Applied Non-Classical Logics 9:61–105, 1999.

    Article  Google Scholar 

  47. Rescher, N., Quasi-truth-functional systems of propositional logic. The Journal of Symbolic Logic 27(1):1–10, 1962.

    Article  Google Scholar 

  48. Rodrigues, A., and H. Antunes, First-order logics of evidence and truth with constant and variable domains. Logica Universalis 16(3):419–449, 2022. https://doi.org/10.1007/s11787-022-00306-8.

    Article  Google Scholar 

  49. Rodrigues, A., and W. Carnielli, On Barrio. Logic and Logical Philosophy 31(2):313–338, 2022. https://doi.org/10.12775/LLP.2022.009.

  50. Rodrigues, A., J. Bueno-Soler, and W. Carnielli, Measuring evidence: a probabilistic approach to an extension of Belnap-Dunn logic. Synthese 198(22):5451–5480, 2020.

    Google Scholar 

  51. Rodrigues, A., M. E. Coniglio, H. Antunes, J. Bueno-Soler, and W. Carnielli, Paraconsistency, evidence, and abduction, in L. Magnani, (ed.), Handbook of Abductive Cognition, Springer, Cham, 2022. https://doi.org/10.1007/978-3-030-68436-5_27-1.

  52. Routley, R., Alternative semantics for quantified first degree relevant logic. Studia Logica 38(2):211–231, 1979.

    Article  Google Scholar 

  53. Sylvan, R., R. Meyer, R. Brady, C. Mortensen, and V. Plumwood, The Algebraic Analysis of Relevant Affixing Systems, in R. Brady, (ed.), Relevant logics and their rivals. A Continuation of the Work of R. Sylvan, R. Meyer, V. Plumwood and R. Brady, Volume II, vol. 59 of Western Philosophy Series, Ashgate Publishing Limited, Aldershot, 2003, pp. 72–140.

  54. Wójcicki, R., Lectures on Propositional Calculi. Ossolineum, Wroclaw, Poland, 1984.

Download references

Acknowledgements

A preprint of this article can be found in [24]. We want to thank the anonymous referees by their comments and suggestions about our manuscript. These comments and corrections helped us to improve the overall quality of the manuscript. The authors acknowledge support from the National Council for Scientific and Technological Development (CNPq, Brazil), research grants 306530/2019-8, 310037/2021-2, and 408040/2021-1. The second author also acknowledges support from Minas Gerais State Agency for Research and Development (FAPEMIG, Brazil), research grant APQ-02093-21.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Marcelo E. Coniglio.

Ethics declarations

Conflict of interest

The authors declare that they have no conflict of interest.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Presented by Walter Carnielli; Received September 26, 2022.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Coniglio, M.E., Rodrigues, A. From Belnap-Dunn Four-Valued Logic to Six-Valued Logics of Evidence and Truth. Stud Logica (2023). https://doi.org/10.1007/s11225-023-10062-5

Download citation

  • Received:

  • Published:

  • DOI: https://doi.org/10.1007/s11225-023-10062-5

Keywords

Navigation