A Distinct-Head Folding Rule

  • David A. Rosenblueth
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 2916)


Tamaki and Sato were perhaps among the first to study folding in logic programs. These authors considered the folding of a single clause (E) using a single-clause definition (D) to give a folded clause (F):

\(\frac{B \leftarrow Q (D) A \leftarrow Q\Theta, R (E)}{A \leftarrow B\Theta, R(F)}\)fold

plus some syntactic conditions, later refined by Gardner and Shepherdson. Here and throughout, A and B denote atoms, and Q and R denote tuples of literals.


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    Pettorossi, A., Proietti, M., Renault, S.: Enhancing partial deduction via unfold/ fold rules. In: Gallagher, J.P. (ed.) LOPSTR 1996. LNCS, vol. 1207, pp. 146–168. Springer, Heidelberg (1997)Google Scholar
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    Roychoudhury, A., Narayan Kumar, K., Ramakrishnan, C.R., Ramakrishnan, I.V.: Beyond Tamaki-Sato style unfold/fold transformations for normal logic programs. Intl. Journal of Foundations of Computer Science 13(3), 387–403 (2002)zbMATHCrossRefMathSciNetGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2003

Authors and Affiliations

  • David A. Rosenblueth
    • 1
  1. 1.Instituto de Investigaciones en Matemáticas Aplicadas y en SistemasUniversidad Nacional Autónoma de MéxicoMéxico D. F.México

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