Package org.tweetyproject.logics.rcl.semantics

Class RelationalRankingFunction

java.lang.Object
org.tweetyproject.commons.AbstractInterpretation<RclBeliefSet,RelationalConditional>
org.tweetyproject.logics.rcl.semantics.RelationalRankingFunction
All Implemented Interfaces:
Interpretation<RclBeliefSet,RelationalConditional>
public class RelationalRankingFunction extends AbstractInterpretation<RclBeliefSet,RelationalConditional>
A relational ranking function (or relational ordinal conditional function, ROCF) that maps Herbrand interpretations to integers.

See W. Spohn. Ordinal conditional functions: a dynamic theory of epistemic states. In W.L. Harper and B. Skyrms, editors, Causation in Decision, Belief Change, and Statistics, II, pages 105-134. Kluwer Academic Publishers, 1988.

See also [Kern-Isberner,Thimm, "A Ranking Semantics for Relational Defaults", in preparation].
Author:
Matthias Thimm

  • Field Details

    • INFINITY

      public static final Integer INFINITY
      Integer used to define infinity.

  • Constructor Details

    • RelationalRankingFunction

      public RelationalRankingFunction(FolSignature signature)
      Creates a new ranking function mapping each given interpretation to zero.
      Parameters:
      signature - the signature of the language this ranking function is defined on.

  • Method Details

    • rank

      public Integer rank(HerbrandInterpretation w) throws IllegalArgumentException
      Gets the rank of the given Herbrand interpretation.
      Parameters:
      w - a Herbrand interpretation.
      Returns:
      the rank of the given Herbrand interpretation.
      Throws:
      IllegalArgumentException - if the given Herbrand interpretation has no rank in this ranking function.

    • setRank

      public void setRank(HerbrandInterpretation w, Integer value)
      Sets the rank for the given Herbrand interpretation.
      Parameters:
      w - a Herbrand interpretation.
      value - the rank for the Herbrand interpretation.

    • rank

      public Integer rank(FolFormula formula) throws IllegalArgumentException
      Gets the rank of the given sentence (ground formula). Throws an IllegalArgumentException when the language of the formula does not correspond to the language of the interpretations this ranking function is defined on or the formula is not a sentence. Otherwise the rank of a formula is defined as the minimal rank of its satisfying interpretations.
      Parameters:
      formula - a formula.
      Returns:
      the rank of the given formula.
      Throws:
      IllegalArgumentException - if the languages of the formula does not correspond to the language of the interpretations this ranking function is defined on or the formula is not a sentence.

    • satisfies

      public boolean satisfies(RelationalConditional formula) throws IllegalArgumentException
      Description copied from interface: Interpretation
      Checks whether this interpretation satisfies the given formula.
      Parameters:
      formula - a formula .
      Returns:
      "true" if this interpretation satisfies the given formula.
      Throws:
      IllegalArgumentException - if the formula does not correspond to the expected language.

    • satisfies

      public boolean satisfies(RclBeliefSet beliefBase) throws IllegalArgumentException
      Description copied from interface: Interpretation
      Checks whether this interpretation satisfies the given knowledge base.
      Parameters:
      beliefBase - a knowledge base.
      Returns:
      "true" if this interpretation satisfies the given knowledge base.
      Throws:
      IllegalArgumentException - IllegalArgumentException if the knowledgebase does not correspond to the expected language.

    • normalize

      public void normalize()
      Normalizes this OCF, i.e. appropriately shifts the ranks such that the minimal rank equals zero.

    • getPossibleInterpretations

      public Set<HerbrandInterpretation> getPossibleInterpretations()
      Returns all interpretations that are mapped to a rank unequal to INFINITY.
      Returns:
      all interpretations that are mapped to a rank unequal to INFINITY.

    • numFalsifiedInstances

      public Integer numFalsifiedInstances(HerbrandInterpretation w, RelationalConditional rc)
      Returns the number of instances of "rc" that are falsified by the given interpretation.
      Parameters:
      w - a Herbrand interpretation.
      rc - a relational conditional.
      Returns:
      the number of instances of "rc" that are falsified by the given interpretation.

    • numVerifiedInstances

      public Integer numVerifiedInstances(HerbrandInterpretation w, RelationalConditional rc)
      Returns the number of instances of "rc" that are verified by the given interpretation.
      Parameters:
      w - a Herbrand interpretation.
      rc - a relational conditional.
      Returns:
      the number of instances of "rc" that are verified by the given interpretation.

    • toString

      public String toString()
      Overrides:
      toString in class Object