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On Guarding Nested Fixpoints

  • Helmut Seidl
  • Andreas Neumann
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1683)

Abstract

For every hierarchicalsystem of equations S over some complete and distributive lattice we construct an equivalent system with the same set of variables which additionally is guarded. The price to be paid is that the resulting right-hand sides may grow exponentially. We therefore present methods how the exponentialbl ow-up can be avoided. Especially, the loop structure of the variable dependence graph is taken into account. Also we prove that size O(m· S) suffices whenever S originates from a fixpoint expression where the nesting-depth of fixpoints is at most m. Finally, we sketch an application to regular tree pattern-matching.

Keywords

Distributive Lattice Free Variable Complete Lattice Hierarchical System Variable Assignment 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer-Verlag Berlin Heidelberg 1999

Authors and Affiliations

  • Helmut Seidl
    • 1
  • Andreas Neumann
    • 1
  1. 1.FB IV - InformatikUniversität TrierTrierGermany

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