An Alternative Characterization of Disjunctive Logic Programs an Alternative Characterization of Disjunctive Logic Programs
نویسندگان
چکیده
We present an alternative characterization of disjunctive logic programs. We rst review Inheritance near-Horn Prolog (InH-Prolog), an intuitive and computationally eeective procedure that extends Prolog using case-analysis. We then describe a xpoint characterization of disjunctive logic programs that is similarly based on case-analysis. This xpoint characterization closely corresponds to the InH-Prolog procedure, and so gives needed insight into the diicult problem of recognizing the minimal disjunctive answers obtainable from the procedure. Due to its case-analysis nature, this characterization maintains a natural and close relationship to the standard characterization of Horn programs. It also gives added insight into the role of deenite answers for disjunctive programs and enables one to neatly focus attention on the interesting class of deenite (single atom) consequences.
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