Package net.sf.tweety.lp.asp.beliefdynamics.revision

Class CredibilityRevision

  • All Implemented Interfaces:
    BaseRevisionOperator<ASPRule>
    public class CredibilityRevision
extends CredibilityRevisionNonIterative<ASPRule>
    Implements the credibility revision approach for ASP described in Kruempelmann et al. 2008. It extends the NonIterativeRevision interface by providing methods to receive the last calculated answer sets and it's projection. Internally the prefixes 'c__' 'neg_c' are used to prefix constants and the prefix 'p__' is used to prefix literals of the extended alphabet of the credibility program.
    Author:
    Tim Janus

    • Field Detail

      • literalMap

        private java.util.Map<ASPLiteral,​java.lang.String> literalMap
        a map used during the creation of the credibility logic program

      • negConstantPrefix

        private java.lang.String negConstantPrefix
        a prefix used to mark constants which represent the id of negative literals.

      • constantPrefix

        private java.lang.String constantPrefix
        a prefix used to mark constants which represents the id of positive literals.

      • predCredibilityPrefix

        private java.lang.String predCredibilityPrefix
        a prefix used to mark the prioritzed version of predicates

      • ruleIndex

        private int ruleIndex
        a rule index counter used during the creation of the credibility logic program

      • solver

        private ASPSolver solver
        reference to the solver used for the answer set generation

      • lastAnswersets

        private java.util.Collection<AnswerSet> lastAnswersets

      • lastProjectedAnswersets

        private java.util.Collection<AnswerSet> lastProjectedAnswersets

      • maxInt

        private int maxInt

    • Constructor Detail

      • CredibilityRevision

        public CredibilityRevision()
        Default Ctor: Do not forget to set the solver

      • CredibilityRevision

        public CredibilityRevision​(ASPSolver solver)
        Ctor: setting the solver at construction time
        Parameters:
        solver - Reference to the solver used for answer set generation.

      • CredibilityRevision

        public CredibilityRevision​(ASPSolver solver,
                           int maxInt)

    • Method Detail

      • getLastAnswerset

        public java.util.Collection<AnswerSet> getLastAnswerset()

      • getLastProjectedAnswerSet

        public java.util.Collection<AnswerSet> getLastProjectedAnswerSet()

      • revise

        public Program revise​(java.util.List<java.util.Collection<ASPRule>> ol)
        Description copied from class: CredibilityRevision
        Revises the belief bases in the orderer list into one belief base.
        Specified by:
        revise in class CredibilityRevision<ASPRule>
        Parameters:
        ol - An orderer list of belief bases which assumes that belief bases with a lower index have a lower priority.
        Returns:
        The belief base which is the result of the revision.

      • projectAnswerSet

        private void projectAnswerSet()
        Projects the answer set of the credibility program to the original alphabet

      • translate

        public Program translate​(java.util.List<Program> orderedList)
        Translates the given list of programs to the credibility logic program. The index of the program in the list represents its credibility, this means the first program in the list has lesser credibility than the second.
        Parameters:
        orderedList - The ordered list of extended logic programs which shall be translated.
        Returns:
        The credibility logic program representing the revision of the given ELPs.

      • translate

        private Program translate​(Program p,
                          int programCredibility)
        Helper method: Translates the given program
        Parameters:
        p - Reference to the program
        programCredibility - The credibility value for the program
        Returns:
        The credibility logic program of the given extendend logic program

      • translateLiteral

        private java.lang.String translateLiteral​(ASPLiteral lit)
        Helper method: creates a string representing the literal and an literal representing the prioritzed version of the literal.
        Parameters:
        lit - The unprioritzed version of the literal.
        Returns:
        A pair containing the string id representing the prioritzed literal and the prioritzed literal.

      • main

        public static void main​(java.lang.String[] args)