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Why the occur-check is not a problem

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Programming Language Implementation and Logic Programming (PLILP 1992)

Part of the book series: Lecture Notes in Computer Science ((LNCS,volume 631))

Abstract

In most Prolog implementations for the efficiency reasons so-called occur-check is omitted from the unification algorithm. We provide here natural syntactic conditions which allow the occur-check to be safely omitted. The established results apply to most well-known Prolog programs and seem to explain why this omission does not lead in practice to any complications.

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Authors and Affiliations

  1. Centre for Mathematics and Computer Science, Kruislaan 413, 1098 SJ, Amsterdam, The Netherlands

    Krzysztof R. Apt

  2. Faculty of Mathematics and Computer Science, University of Amsterdam, Plantage Muidergracht 24, 1018 TV, Amsterdam, The Netherlands

    Krzysztof R. Apt

  3. Dipartimento di Matematica Pura ed Applicata Università di Padova, Via Belzoni 7, 35131, Padova, Italy

    Alessandro Pellegrini

Authors
  1. Krzysztof R. Apt
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  2. Alessandro Pellegrini
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Maurice Bruynooghe Martin Wirsing

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© 1992 Springer-Verlag Berlin Heidelberg

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Apt, K.R., Pellegrini, A. (1992). Why the occur-check is not a problem. In: Bruynooghe, M., Wirsing, M. (eds) Programming Language Implementation and Logic Programming. PLILP 1992. Lecture Notes in Computer Science, vol 631. Springer, Berlin, Heidelberg. https://doi.org/10.1007/3-540-55844-6_128

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  • DOI: https://doi.org/10.1007/3-540-55844-6_128

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  • Publisher Name: Springer, Berlin, Heidelberg

  • Print ISBN: 978-3-540-55844-6

  • Online ISBN: 978-3-540-47297-1

  • eBook Packages: Springer Book Archive

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