A computationally attractive first-order logic of belief

  • Gerhard Lakemeyer
Selected Papers
Part of the Lecture Notes in Computer Science book series (LNCS, volume 478)


Logics of belief play an essential role in formal approaches to knowledge representation (KR). Such logics allow us to formalize the idea that a knowledge base (KB) represents an epistemic state, that is, a set of beliefs. In its simplest form, an epistemic state can be defined as the set of all beliefs that logically follow from believing the sentences that are explicitly stored in the KB. Reasoning can be understood as computing whether a belief follows logically from believing the sentences in the KB. Since the classical model of belief, possible-world semantics, renders reasoning undecidable, it is important to find weaker models with better computational properties.

This paper proposes such a model by combining features from both possible-world semantics and relevance logic. Among the important features of this logic are its treatment of quantifying-in, which allows us to distinguish between “knowing that” and “knowing who,” and the decidability of the implication problem for belief. The decidability result follows from a close connection between this notion of belief and an existing decidable form of first-order entailment.


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Copyright information

© Springer-Verlag Berlin Heidelberg 1991

Authors and Affiliations

  • Gerhard Lakemeyer
    • 1
  1. 1.Department of Computer ScienceUniversity of TorontoTorontoCanada

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