Class DefeasibleLogicProgram

java.lang.Object
org.tweetyproject.commons.BeliefSet<DelpRule,FolSignature>
org.tweetyproject.arg.delp.syntax.DefeasibleLogicProgram
All Implemented Interfaces:
Iterable<DelpRule>, Collection<DelpRule>, BeliefBase

public class DefeasibleLogicProgram extends BeliefSet<DelpRule,FolSignature>
This class models a defeasible logic program (DeLP).
Author:
Matthias Thimm
  • Constructor Details

    • DefeasibleLogicProgram

      public DefeasibleLogicProgram()
      Default constructor; initializes empty delpFacts, strict and defeasible rules and empty comparison criterion.
    • DefeasibleLogicProgram

      public DefeasibleLogicProgram(DefeasibleLogicProgram delp)
      constructor; initializes this program with the given program
      Parameters:
      delp - a defeasible logic program
  • Method Details

    • ground

      public DefeasibleLogicProgram ground()
      In general, a delp comprises of rule schemes with variables. This methods returns the corresponding grounded theory, i.e., all schematic elements are replaced with all their grounded instances, where all occurring variables are replaced with constants in every possible way. The set of constants used is the set of constants appearing in this delp.
      Returns:
      the grounded version of this
    • ground

      public DefeasibleLogicProgram ground(Set<Constant> constants)
      In general, a delp comprises of rule schemes with variables. This methods returns the corresponding grounded theory, i.e., all schematic elements are replaced with all their grounded instances, where all occurring variables are replaced with constants in every possible way.
      Parameters:
      constants - some set of constants.
      Returns:
      the grounded version of this
    • getDungTheory

      public DungTheory getDungTheory()
      This method translates this delp into an abstract Dung theory. All arguments, that can be built in this theory are interpreted as abstract arguments. The attack relation is built using the dialectical proof theory of delp.
      Returns:
      the abstract Dung theory induced by this delp.
    • getArguments

      public Set<DelpArgument> getArguments()
      Returns the set of all possible arguments, that can be built in this delp.
      Returns:
      the set of all possible arguments, that can be built in this delp.
    • getStrictClosure

      public Set<FolFormula> getStrictClosure(Set<FolFormula> literals, Set<DefeasibleRule> defeasibleRules, boolean usefacts)
      Computes the strict closure of the program, i.e., the set of all strictly derivable literals. For this computation the program may be extended by the given parameters
      Parameters:
      literals - a set of literals
      defeasibleRules - a set of defeasible rules
      usefacts - set to true iff the delpFacts of this program shall be used in computing the closure
      Returns:
      the closure of this program and the given parameters
    • getStrictClosure

      public Set<FolFormula> getStrictClosure(Set<FolFormula> literals, Set<DefeasibleRule> defeasibleRules)
      Computes the strict closure of the program, i.e., the set of all strictly derivable literals. The program is extended with delpFacts and defeasible rules (which are interpreted as strict rules here) described by the parameters literals and defeasibleRules.
      Parameters:
      literals - a set of literals
      defeasibleRules - a set of defeasible rules
      Returns:
      the set of all strictly derivable literals.
    • getStrictClosure

      public Set<FolFormula> getStrictClosure(Set<FolFormula> literals)
      Computes the strict closure of the program, i.e., the set of all strictly derivable literals. The program is extended with delpFacts described by the parameter literals
      Parameters:
      literals - a set of literals
      Returns:
      the set of all strictly derivable literals.
    • getStrictClosure

      public Set<FolFormula> getStrictClosure()
      Computes the strict closure of the program, i.e., the set of all strictly derivable literals.
      Returns:
      the set of all strictly derivable literals.
    • isConsistent

      public boolean isConsistent(Set<DefeasibleRule> rules)
      Checks whether the given set of defeasible rules are consistent given the strict part of this program.
      Parameters:
      rules - a set of defeasible rules
      Returns:
      false if the union of this program's delpFacts and strict rules with the given set of defeasible rules defeasibly derives two complementary literals
    • disagree

      public boolean disagree(Set<FolFormula> literals)
      Checks whether the given set of literals disagree with respect to the strict part of this program.
      Parameters:
      literals - a set of literals
      Returns:
      true if the union of this program's delpFacts and strict rules with the given set of literals defeasibly derives two complementary literals
    • isGround

      public boolean isGround()
    • toString

      public String toString()
      Specified by:
      toString in interface BeliefBase
      Overrides:
      toString in class BeliefSet<DelpRule,FolSignature>
    • getRulesWithHead

      public Set<DelpRule> getRulesWithHead(FolFormula l)
      Returns all defeasible and strict rules appearing in this program with the given literal as head
      Parameters:
      l - a literal
      Returns:
      a set of strict and defeasible rules
    • getMinimalSignature

      public Signature getMinimalSignature()
      Description copied from interface: BeliefBase
      Returns the signature of the language of this knowledge base.
      Returns:
      the signature of the language of this knowledge base.
    • main

      public static void main(String[] args) throws IOException, org.kohsuke.args4j.CmdLineException
      Parsing DeLP from given file and performing given query against it.
      Parameters:
      args - Options and arguments (try "-h" to get a help text with details)
      Throws:
      IOException - if an IO issue occurs.
      org.kohsuke.args4j.CmdLineException - if there is some problem parsing the command line