Journal of Logic, Language and Information

, Volume 8, Issue 2, pp 167–185 | Cite as

A Logic with Relative Knowledge Operators

  • Stéphane Demri


We study a knowledge logic that assumes that to each set of agents, an indiscernibility relation is associated and the agents decide the membership of objects or states up to this indiscernibility relation. Its language contains a family of relative knowledge operators. We prove the decidability of the satisfiability problem, we show its EXPTIME-completeness and as a side-effect, we define a complete Hilbert-style axiomatization.

Modal logic relative knowledge operator decidability complexity Hilbert-style 


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Copyright information

© Kluwer Academic Publishers 1999

Authors and Affiliations

  • Stéphane Demri
    • 1
  1. 1.Laboratoire Leibniz – C.N.R.S.GrenobleFrance (E-mail

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