Journal article

Natural deduction systems for E

Shawn Standefer, Ross T Brady

Logique et Analyse | Peeters | Published : 2018


Anderson and Belnap [1975] presented a Fitch natural deduction system, FE, for their logic E of entailment as well as Fitch systems for the relevant logics T and R. The system FE is obtained from the system for R through a restriction on the rule of reiteration. Brady [1984] presents Fitch systems for a range of relevant logics, none of which uses a restriction on the rule of reiteration. However, no Fitch system for E was presented. We fill this lacuna by providing two Fitch systems for E, neither of which uses a restriction on the rule of reiteration. We close by discussing their differences and possible connections to other extant systems for E.


Awarded by Australian Research Council

Funding Acknowledgements

We would like to thank Greg Restall, Ed Mares, and the audience at the Melbourne Logic Seminar for feedback and discussion. We would also like to thank the anonymous referees at this journal for their helpful comments on the paper. Shawn Standefer's research was supported by the Australian Research Council, Discovery Grant DP150103801.