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A fast algorithm for uniform semi-unification

  • Alberto Oliart
  • Wayne Snyder
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1421)

Abstract

We present a fast algorithm for uniform semi-unification based on adapting the Huet unification closure method for standard unification. It solves the following decision problem in O(n2α(n)2), where n is the size of the two terms, and α is the functional inverse of Ackermann's function: Given two terms s and t, do there exist two substitutions σ and ρ such that ρ(σ(s)) = σ(t)? In the affirmative case, a solution σ can be constructed within the same time bound. However, if a principal solution (analogous to an mgu) is required, some modifications to the algorithm must be made, and the upper bound increases to O(n2log2(nα(n))α(n)2).

Keywords

Fast Algorithm Decision Procedure Function Symbol Function Node Symbolic Operation 
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Copyright information

© Springer-Verlag Berlin Heidelberg 1998

Authors and Affiliations

  • Alberto Oliart
    • 1
  • Wayne Snyder
    • 1
  1. 1.Computer Science DepartmentBoston UniversityBoston

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