Semantical and Computational Aspects of Horn Approximations

  title={Semantical and Computational Aspects of Horn Approximations},
  author={Marco Cadoli},
In a recent study Selman and Kautz proposed a method, called Horn approximation, for speeding up inference in propositional Knowledge Bases. Their technique is based on the compilation of a propositional formula into a pair of Horn formulae: a Horn Greatest Lower Bound (GLB) and a Horn Least Upper Bound (LUB). In this paper we address two questions that have been only marginally addressed so far: 1) what is the semantics of the Horn approxima-tions? 2) what is the exact complexity of nd-ing… CONTINUE READING