Journal of Philosophical Logic

, Volume 24, Issue 2, pp 139–160 | Cite as

Four-valued semantics for relevant logics (and some of their rivals)

  • Greg Restall


This paper gives an outline of three different approaches to the four-valued semantics for relevant logics (and other non-classical logics in their vicinity). The first approach borrows from the ‘Australian Plan’ semantics, which uses a unary operator ‘⋆’ for the evaluation of negation. This approach can model anything that the two-valued account can, but at the cost of relying on insights from the Australian Plan. The second approach is natural, well motivated, independent of the Australian Plan, and it provides a semantics for the contraction-free relevant logicC (orRW). Unfortunately, its approach seems to model little else. The third approach seems to capture a wide range of formal systems, but at the time of writing, lacks a completeness proof.


Formal System Unary Operator Completeness Proof Relevant Logic Australian Plan 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Kluwer Academic Publishers 1995

Authors and Affiliations

  • Greg Restall
    • 1
  1. 1.Automated Reasoning ProjectAustralian National UniversityCanberraAustralia

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