Sequent Systems for Lewis’ Conditional Logics

  • Björn Lellmann
  • Dirk Pattinson
Part of the Lecture Notes in Computer Science book series (LNCS, volume 7519)


We present unlabelled cut-free sequent calculi for Lewis’ conditional logic \(\mathbb V\) and extensions, in both the languages with the entrenchment connective and the strong conditional. The calculi give rise to Pspace-decision procedures, also in the language with the weak conditional. Furthermore, they are used to prove the Craig interpolation property for all the logics under consideration, and yield a Pspace-decision procedure for a recently considered hybrid version of \(\mathbb V\).


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© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  • Björn Lellmann
    • 1
  • Dirk Pattinson
    • 1
  1. 1.Department of ComputingImperial College LondonUK

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