Package aima.core.logic.propositional.parsing.ast

Examples of aima.core.logic.propositional.parsing.ast.Sentence

28
29
30
31
32
33
34
35
36
37
38
39
   *
   * @return the answer to the specified question using the TT-Entails
   *         algorithm.
   */
  public boolean ttEntails(KnowledgeBase kb, String alpha) {
    Sentence kbSentence = kb.asSentence();
    Sentence querySentence = (Sentence) new PEParser().parse(alpha);
    SymbolCollector collector = new SymbolCollector();
    Set<Symbol> kbSymbols = collector.getSymbolsIn(kbSentence);
    Set<Symbol> querySymbols = collector.getSymbolsIn(querySentence);
    Set<Symbol> symbols = SetOps.union(kbSymbols, querySymbols);
    List<Symbol> symbolList = new Converter<Symbol>().setToList(symbols);
View Full Code Here
28
29
30
31
32
33
34
35
36
37
38
39
  public Object visitNotSentence(UnarySentence us, Object arg) {
    return transformNotSentence(us);
  }

  public Sentence transform(Sentence s) {
    Sentence toTransform = s;
    while (!(toTransform.equals(step(toTransform)))) {
      toTransform = step(toTransform);
    }

    return toTransform;
  }
View Full Code Here
41
42
43
44
45
46
47
48
49
50
51
52
53
  private Sentence step(Sentence s) {
    return (Sentence) s.accept(this, null);
  }

  private Sentence transformBiConditionalSentence(BinarySentence bs) {
    Sentence first = new BinarySentence("=>", (Sentence) bs.getFirst()
        .accept(this, null), (Sentence) bs.getSecond().accept(this,
        null));
    Sentence second = new BinarySentence("=>", (Sentence) bs.getSecond()
        .accept(this, null), (Sentence) bs.getFirst()
        .accept(this, null));
    return new BinarySentence("AND", first, second);
  }
View Full Code Here
51
52
53
54
55
56
57
58
59
60
        .accept(this, null));
    return new BinarySentence("AND", first, second);
  }

  private Sentence transformImpliedSentence(BinarySentence bs) {
    Sentence first = new UnarySentence((Sentence) bs.getFirst().accept(
        this, null));
    return new BinarySentence("OR", first, (Sentence) bs.getSecond()
        .accept(this, null));
  }
View Full Code Here
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
      return (Sentence) ((UnarySentence) us.getNegated()).getNegated()
          .accept(this, null);
    } else if (us.getNegated() instanceof BinarySentence) {
      BinarySentence bs = (BinarySentence) us.getNegated();
      if (bs.isAndSentence()) {
        Sentence first = new UnarySentence((Sentence) bs.getFirst()
            .accept(this, null));
        Sentence second = new UnarySentence((Sentence) bs.getSecond()
            .accept(this, null));
        return new BinarySentence("OR", first, second);
      } else if (bs.isOrSentence()) {
        Sentence first = new UnarySentence((Sentence) bs.getFirst()
            .accept(this, null));
        Sentence second = new UnarySentence((Sentence) bs.getSecond()
            .accept(this, null));
        return new BinarySentence("AND", first, second);
      } else {
        return (Sentence) super.visitNotSentence(us, null);
      }
View Full Code Here
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
  }

  private Sentence distributeOrOverAnd(BinarySentence bs) {
    BinarySentence andTerm = bs.firstTermIsAndSentence() ? (BinarySentence) bs
        .getFirst() : (BinarySentence) bs.getSecond();
    Sentence otherterm = bs.firstTermIsAndSentence() ? bs.getSecond() : bs
        .getFirst();
    // (alpha or (beta and gamma) = ((alpha or beta) and (alpha or gamma))
    Sentence alpha = (Sentence) otherterm.accept(this, null);
    Sentence beta = (Sentence) andTerm.getFirst().accept(this, null);
    Sentence gamma = (Sentence) andTerm.getSecond().accept(this, null);
    Sentence distributed = new BinarySentence("AND", new BinarySentence(
        "OR", alpha, beta), new BinarySentence("OR", alpha, gamma));
    return distributed;
  }
View Full Code Here
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
  private Random random = new Random();

  public Model findModelFor(String logicalSentence, int numberOfFlips,
      double probabilityOfRandomWalk) {
    myModel = new Model();
    Sentence s = (Sentence) new PEParser().parse(logicalSentence);
    CNFTransformer transformer = new CNFTransformer();
    CNFClauseGatherer clauseGatherer = new CNFClauseGatherer();
    SymbolCollector sc = new SymbolCollector();

    List<Symbol> symbols = new Converter<Symbol>().setToList(sc.getSymbolsIn(s));
    for (int i = 0; i < symbols.size(); i++) {
      Symbol sym = (Symbol) symbols.get(i);
      myModel = myModel.extend(sym, Util.randomBoolean());
    }
    List<Sentence> clauses = new Converter<Sentence>()
        .setToList(clauseGatherer.getClausesFrom(transformer
            .transform(s)));

    for (int i = 0; i < numberOfFlips; i++) {
      if (getNumberOfClausesSatisfiedIn(
          new Converter<Sentence>().listToSet(clauses), myModel) == clauses
          .size()) {
        return myModel;
      }
      Sentence clause = clauses.get(random.nextInt(clauses.size()));

      List<Symbol> symbolsInClause = new Converter<Symbol>().setToList(sc
          .getSymbolsIn(clause));
      if (random.nextDouble() >= probabilityOfRandomWalk) {
        Symbol randomSymbol = symbolsInClause.get(random
View Full Code Here
87
88
89
90
91
92
93
94
95
96
97
  private int getNumberOfClausesSatisfiedIn(Set<Sentence> clauses, Model model) {
    int retVal = 0;
    Iterator<Sentence> i = clauses.iterator();
    while (i.hasNext()) {
      Sentence s = i.next();
      if (model.isTrue(s)) {
        retVal += 1;
      }
    }
    return retVal;
View Full Code Here
41
42
43
44
45
46
47
48
49
50
51
  public Object visitMultiSentence(MultiSentence fs, Object arg) {
    List<Sentence> terms = fs.getSentences();
    List<Sentence> newTerms = new ArrayList<Sentence>();
    for (int i = 0; i < terms.size(); i++) {
      Sentence s = (Sentence) terms.get(i);
      Sentence subsTerm = (Sentence) s.accept(this, arg);
      newTerms.add(subsTerm);
    }
    return new MultiSentence(fs.getOperator(), newTerms);
  }
View Full Code Here
26
27
28
29
30
31
32
33
34
35
   *
   * @param aSentence
   *            a fact to be added to the knowledge base.
   */
  public void tell(String aSentence) {
    Sentence sentence = (Sentence) parser.parse(aSentence);
    if (!(sentences.contains(sentence))) {
      sentences.add(sentence);
    }
  }
View Full Code Here
TOP

Related Classes of aima.core.logic.propositional.parsing.ast.Sentence

  • aima.core.logic.propositional.algorithms.DPLL
  • aima.core.logic.propositional.algorithms.KnowledgeBase
  • aima.core.logic.propositional.algorithms.LogicUtils
  • aima.core.logic.propositional.algorithms.PLFCEntails
  • aima.core.logic.propositional.algorithms.PLResolution
  • aima.core.logic.propositional.algorithms.TTEntails
  • aima.core.logic.propositional.algorithms.WalkSAT
  • aima.core.logic.propositional.parsing.AbstractPLVisitor
  • aima.core.logic.propositional.parsing.PEParser
  • aima.core.logic.propositional.visitors.CNFTransformer
    • Copyright © 2018 www.massapicom. All rights reserved.
    All source code are property of their respective owners. Java is a trademark of Sun Microsystems, Inc and owned by ORACLE Inc. Contact coftware#gmail.com.