Skip to main content

Two's Company: “The Humbug of Many Logical Values”

  • Conference paper
Logica Universalis

Abstract

The Polish logician Roman Suszko has extensively pleaded in the 1970s for a restatement of the notion of many-valuedness. According to him, as he would often repeat, “there are but two logical values, true and false.” As a matter of fact, a result by Wójcicki-Lindenbaum shows that any tarskian logic has a many-valued semantics, and results by Suszko-da Costa-Scott show that any many-valued semantics can be reduced to a two-valued one. So, why should one even consider using logics with more than two values? Because, we argue, one has to decide how to deal with bivalence and settle down the trade-off between logical 2-valuedness and truth-functionality, from a pragmatical standpoint.

This paper will illustrate the ups and downs of a two-valued reduction of logic. Suszko's reductive result is quite non-constructive. We will exhibit here a way of effectively constructing the two-valued semantics of any logic that has a truth-functional finite-valued semantics and a sufficiently expressive language. From there, as we will indicate, one can easily go on to provide those logics with adequate canonical systems of sequents or tableaux. The algorithmic methods developed here can be generalized so as to apply to many non-finitely valued logics as well —or at least to those that admit of computable quasi tabular two-valued semantics, the so-called dyadic semantics.

The work of the first and the fourth authors was partially supported by FEDER (European Union) and FCT (Portugal), namely via the Projects POCTI / MAT / 37239 / 2001 FibLog and POCTI / MAT / 55796 / 2004 QuantLog of the Center for Logic and Computation (CLC / IST, Portugal), and the grant SFRH / BD / 8825 / 2002. The second author was partially supported by CNPq (Brazil) and by a senior scientist research grant from the CLC / IST.

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

Access this chapter

Chapter
USD 29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
eBook
USD 54.99
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. D. Batens, A bridge between two-valued and many-valued semantic systems: n-tuple semantics, Proceedings of the XII International Symposium on Multiple-Valued Logic, IEEE Computer Science Press, 1982, pp. 318–322.

    Google Scholar 

  2. N. D. Belnap, A useful four-valued logic, Modern Uses of Multiple-Valued Logic (J. M. Dunn, ed.), D. Reidel Publishing, Boston, 1977, pp. 8–37.

    Google Scholar 

  3. J.-Y. Béziau, Universal Logic, Logica'94, Proceedings of the VIII International Symposium (T. Childers and O. Majers, eds.), Czech Academy of Science, Prague, CZ, 1994, pp. 73–93.

    Google Scholar 

  4. J.-Y. Béziau, Recherches sur la logique abstraite: les logiques normales, Acta Universitatis Wratislaviensis no. 2023, Logika 18 (1998), 105–114.

    MATH  Google Scholar 

  5. J.-Y. Béziau, Sequents and bivaluations, Logique et Analyse (N.S.) 44 (2001), no. 176, 373–394.

    MATH  MathSciNet  Google Scholar 

  6. C. Caleiro, W. A. Carnielli, M. E. Coniglio, and J. Marcos, Dyadic semantics for many-valued logics, Preprint available at: http://wslc.math.ist.utl.pt/ftp/pub/CaleiroC/03-CCCM-dyadic2.pdf.

    Google Scholar 

  7. C. Caleiro, W. A. Carnielli, M. E. Coniglio, and J. Marcos, How many logical values are there? Dyadic semantics for many-valued logics, Preprint.

    Google Scholar 

  8. C. Caleiro, W. A. Carnielli, M. E. Coniglio, and J. Marcos, Suszko's Thesis and dyadic semantics, Preprint available at: http://wslc.math.ist.utl.pt/ftp/pub/CaleiroC/03-CCCM-dyadicl.pdf.

    Google Scholar 

  9. C. Caleiro and J. Marcos, Non-truth-functional fibred semantics, Proceedings of the International Conference on Artificial Intelligence (IC-AI'2001), held in Las Vegas, USA, June 2001 (H. R. Arabnia, ed.), vol. II, CSREA Press, Athens GA, USA, 2001, pp. 841–847. http://wslc.math.ist.utl.pt/ftp/pub/CaleiroC/01-CM-fiblogl0.ps.

    Google Scholar 

  10. W. A. Carnielli, Systematization of the finite many-valued logics through the method of tableaux, The Journal of Symbolic Logic 52 (1987), 473–493.

    MATH  MathSciNet  Google Scholar 

  11. W. A. Carnielli and M. Lima-Marques, Society semantics for multiple-valued logics, Advances in Contemporary Logic and Computer Science (W. A. Carnielli and I. M. L. D'Ottaviano, eds.), Contemporary Mathematics Series, vol. 235, American Mathematical Society, 1999, pp. 33–52.

    Google Scholar 

  12. W. A. Carnielli and J. Marcos, Tableaux for logics of formal inconsistency, Proceedings of the 2001 International Conference on Artificial Intelligence (IC-AI'2001), held in Las Vegas, USA, June 2001 (H. R. Arabnia, ed.), vol. II, CSREA Press, Athens GA, USA, 2001, pp. 848–852. http://logica.rug.ac.be/~joao/Publications/Congresses/tableauxLFIs.pdf.

    Google Scholar 

  13. W. A. Carnielli, J. Marcos, and S. de Amo, Formal inconsistency and evolutionary databases, Logic and Logical Philosophy 8 (2000), 115–152. http://www.cle.unicamp.br/e-prints/abstract_6.htm.

    Google Scholar 

  14. N. C. A. da Costa, Calculs propositionnels pour les systèmes formels inconsistants, Comptes Rendus d'Academie des Sciences de Paris 257 (1963), 3790–3792.

    MATH  Google Scholar 

  15. N. C. A. da Costa and E. H. Alves, A semantical analysis of the calculi C n , Notre Dame Journal of Formal Logic 18 (1977), 621–630.

    MathSciNet  Google Scholar 

  16. N. C. A. da Costa, J.-Y. Béziau, and O. A. S. Bueno, Malinowski and Suszko on many-valued logics: On the reduction of many-valuedness to two-valuedness, Modern Logic 3 (1996), 272–299.

    Google Scholar 

  17. V. L. Fernández and M. E. Coniglio, Combining valuations with society semantics, Journal of Applied Non-Classical Logics 13 (2003), no. 1, 21–46. http://www.cle.unicamp.br/e-prints/abstract_11.html.

    Google Scholar 

  18. G. Malinowski, Many-Valued Logics, Oxford Logic Guides 25, Clarendon Press, Oxford, 1993.

    Google Scholar 

  19. J. Marcos, Possible-Translations Semantics (in Portuguese), Master's thesis, State University of Campinas (Brazil), 1999. http://www.cle.unicamp.br/students/J.Marcos/.

    Google Scholar 

  20. D. Scott, Background to formalisation, Truth, Syntax and Modality (H. Leblanc, ed.), North-Holland, Amsterdam, 1973, pp. 244–273.

    Google Scholar 

  21. D. Scott, Completeness and axiomatizability in many-valued logic, Proceedings of Tarski Symposium (L. Henkin et. al., ed.), Proceedings of Symposia in Pure Mathematics, vol.25, Berkeley 1971, 1974, pp. 411–436.

    Google Scholar 

  22. A. M. Sette, On the propositional calculus P1, Mathematica Japonicae 18 (1973), 173–180.

    MATH  MathSciNet  Google Scholar 

  23. R.. Suszko, Abolition of the Fregean Axiom, Logic Colloquium: Symposium on Logic held at Boston, 1972–73 (R.. Parikh, ed.), Lecture Notes in Mathematics, vol. 453, Springer-Verlag, 1972, pp. 169–239.

    Google Scholar 

  24. R.. Suszko, Remarks on Lukasiewicz's three-valued logic, Bulletin of the Section of Logic 4 (1975), 87–90.

    MATH  MathSciNet  Google Scholar 

  25. R. Suszko, The Fregean axiom and Polish mathematical logic in the 1920's, Studia Logica 36 (1977), 373–380.

    Article  MathSciNet  Google Scholar 

  26. M. Tsuji, Many-valued logics and Suszko's Thesis revisited, Studia Logica 60 (1998), no. 2, 299–309.

    Article  MATH  MathSciNet  Google Scholar 

  27. R. Wójcicki, Logical matrices strongly adequate for structural sentential calculi, Bulletin de l'Academie Polonaise des Sciences, Série des Sciences Mathematiques, Astronomiques et Physiques 17 (1969), 333–335.

    MATH  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Editor information

Editors and Affiliations

Rights and permissions

Reprints and permissions

Copyright information

© 2005 Birkhäuser Verlag Basel/Switzerland

About this paper

Cite this paper

Caleiro, C., Carnielli, W., Coniglio, M., Marcos, J. (2005). Two's Company: “The Humbug of Many Logical Values”. In: Beziau, JY. (eds) Logica Universalis. Birkhäuser Basel. https://doi.org/10.1007/3-7643-7304-0_10

Download citation

Publish with us

Policies and ethics