Explanatory Model for the Break of Logic Equivalence by Irrational Agents in Elkan’s Paradox

  • Germano Resconi
  • Boris Kovalerchuk
Part of the Lecture Notes in Computer Science book series (LNCS, volume 4739)


Fuzzy logic breaks logic equivalence of statements such as (A∧B)∨(¬A∧B)∨(A∧ ¬B) and A∨B. It breaks the symmetry of use of such logically equivalent statements. There is a controversy about this property. It is called a paradox (Elkan’s paradox) and interpreted as a logical weakness of fuzzy logic. In the opposite view, it is not a paradox but a fundamental postulate of fuzzy logic and one of the sources of its success in applications. There is no explanatory model to resolve this controversy. This paper provides such a model using a vector/matrix logic of rational and irrational agents that covers scalar classical and fuzzy logics. It is shown that the classical logic models rational agents, while fuzzy logic can model irrational agents. Rational agents do not break logic equivalence in contrast with irrational agents. We resolve the paradox by showing that the classical and fuzzy logics have different domains of rational and irrational agents.


Fuzzy logic classical logic explanatory model logic equivalence irrational agent inconsistent agent rational agent paradox 


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Copyright information

© Springer-Verlag Berlin Heidelberg 2007

Authors and Affiliations

  • Germano Resconi
    • 1
  • Boris Kovalerchuk
    • 2
  1. 1.Dept. of Mathematics and Physics, Catholic University, via Trieste 17, BresciaItaly
  2. 2.Dept. of Computer Science, Central Washington University, Ellensburg, WA 98922USA

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