Journal of Logic, Language and Information

, Volume 21, Issue 3, pp 365–391

A Diagrammatic Inference System with Euler Circles


DOI: 10.1007/s10849-012-9160-6

Cite this article as:
Mineshima, K., Okada, M. & Takemura, R. J of Log Lang and Inf (2012) 21: 365. doi:10.1007/s10849-012-9160-6


Proof-theory has traditionally been developed based on linguistic (symbolic) representations of logical proofs. Recently, however, logical reasoning based on diagrammatic or graphical representations has been investigated by logicians. Euler diagrams were introduced in the eighteenth century. But it is quite recent (more precisely, in the 1990s) that logicians started to study them from a formal logical viewpoint. We propose a novel approach to the formalization of Euler diagrammatic reasoning, in which diagrams are defined not in terms of regions as in the standard approach, but in terms of topological relations between diagrammatic objects. We formalize the unification rule, which plays a central role in Euler diagrammatic reasoning, in a style of natural deduction. We prove the soundness and completeness theorems with respect to a formal set-theoretical semantics. We also investigate structure of diagrammatic proofs and prove a normal form theorem.


Proof-theory Diagrammatic reasoning Euler diagram 

Copyright information

© Springer Science+Business Media B.V. 2012

Authors and Affiliations

  1. 1.Department of PhilosophyKeio UniversityTokyoJapan

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