Skip to main content
Log in

Commuting Conversions vs. the Standard Conversions of the “Good” Connectives

  • Published:
Studia Logica Aims and scope Submit manuscript

Abstract

Commuting conversions were introduced in the natural deduction calculus as ad hoc devices for the purpose of guaranteeing the subformula property in normal proofs. In a well known book, Jean-Yves Girard commented harshly on these conversions, saying that ‘one tends to think that natural deduction should be modified to correct such atrocities.’ We present an embedding of the intuitionistic predicate calculus into a second-order predicative system for which there is no need for commuting conversions. Furthermore, we show that the redex and the conversum of a commuting conversion of the original calculus translate into equivalent derivations by means of a series of bidirectional applications of standard conversions.

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

References

  1. Ferreira F.: ‘Comments on Predicative Logic’. Journal of Philosophical Logic 35, 1–8 (2006)

    Article  Google Scholar 

  2. Girard, J.-Y., Y. Lafont, and P. Taylor, Proofs and Types, Cambridge University Press, 1989.

  3. Prawitz, D., Natural Deduction, Almkvist & Wiksell, Stockholm, 1965. Reprinted, with a new preface, in Dover Publications, 2006.

  4. Sandqvist, T., ‘A Note on Definability of Logical Operators in Second-order Logic’, Unpublished manuscript, 2008.

  5. Troelstra, A., and H. Schwichtenberg, Basic Proof Theory, Cambridge University Press, 1996.

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Fernando Ferreira.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Ferreira, F., Ferreira, G. Commuting Conversions vs. the Standard Conversions of the “Good” Connectives. Stud Logica 92, 63–84 (2009). https://doi.org/10.1007/s11225-009-9186-1

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11225-009-9186-1

Keywords

Navigation