Ejemplo n.º 1
0
 public List<Sentence> Parse()
 {
     Sentence s = new Sentence();
     s.Predicates.Add(ParsePredicate(true));
     sentences.Add(s);
     while (currentToken.Type != TokenType.EndOfFile)
     {
         sentences.Add(ParseSentence());
     }
     return sentences;
 }
Ejemplo n.º 2
0
 // Sentence
 // Predicate { '|' Predicate } '.'
 public Sentence ParseSentence()
 {
     Sentence s = new Sentence();
     s.Predicates.Add(ParsePredicate(false));
     while (currentToken.Type == TokenType.Or)
     {
         Advance();
         s.Predicates.Add(ParsePredicate(false));
     }
     //Advance(); // '.'
     return s;
 }
Ejemplo n.º 3
0
        /// <summary>
        /// This method will attempt to resolve two sentences passed in as parameters. If the sentence cannot be resolved
        /// then the return value will be null. Otherwise it will return the resolved sentence.
        /// </summary>
        /// <param name="Ci"> One of the sentences to compare for resolution. </param>
        /// <param name="Cj"> The other sentence to compare for resolution. </param>
        /// <returns> null if the sentence couldn't be resolved or the resolved sentence. </returns>
        private Sentence Resolve(Sentence Ci, Sentence Cj)
        {
            Sentence newSentence = new Sentence();
            List<Predicate> resolvedPreds = new List<Predicate>();
            bool resolvedSentence = false;

            foreach (Predicate cIPred in Ci.Predicates) {
                foreach (Predicate cJPred in Cj.Predicates) {
                    if ((cIPred.Label == cJPred.Label) && (cIPred.Not != cJPred.Not) && RulesMatch(cIPred.Rules, cJPred.Rules)) {
                        // Dictionary <Rule from cJPred being replaced, the value it will be replaced with in cIPred>
                        Dictionary<string, Rule> unifyI = new Dictionary<string, Rule>();
                        Dictionary<string, Rule> unifyJ = new Dictionary<string, Rule>();

                        resolvedPreds.Add(cIPred);
                        resolvedPreds.Add(cJPred);

                        // Find the rules that unify in Cj sentence
                        for (int i = 0; i < cJPred.Rules.Count(); ++i) {
                            if (!unifyJ.ContainsKey(cJPred.Rules[i].ToString()))
                                unifyJ.Add(cJPred.Rules[i].ToString(), cIPred.Rules[i]);
                        }

                        // Find the rules that unify in Cj sentence
                        for (int i = 0; i < cIPred.Rules.Count(); ++i) {
                            if (!unifyI.ContainsKey(cIPred.Rules[i].ToString()))
                                unifyI.Add(cIPred.Rules[i].ToString(), cJPred.Rules[i]);
                        }

                        // Replace the rules in the Ci sentence that unify.
                        Sentence cISentence = new Sentence();
                        foreach (Predicate pred in Ci.Predicates) {
                            if (!resolvedPreds.Contains(pred)) {
                                Predicate newPredicate = new Predicate();

                                newPredicate.Label = pred.Label;
                                newPredicate.Not = pred.Not;

                                for (int i = 0; i < pred.Rules.Count(); ++i) {
                                    string key = pred.Rules[i].Label;

                                    if (unifyI.ContainsKey(key))
                                        newPredicate.Rules.Add(unifyI[key]);

                                    else
                                        newPredicate.Rules.Add(pred.Rules[i]);
                                }

                                cISentence.Predicates.Add(newPredicate);
                            }
                        }

                        // Replace the rules in the Cj sentence that unify.
                        Sentence cJSentence = new Sentence();
                        foreach (Predicate pred in Cj.Predicates) {
                            if (!resolvedPreds.Contains(pred)) {
                                Predicate newPredicate = new Predicate();

                                newPredicate.Label = pred.Label;
                                newPredicate.Not = pred.Not;

                                for (int i = 0; i < pred.Rules.Count(); ++i) {
                                    string key = pred.Rules[i].ToString();

                                    if (unifyJ.ContainsKey(key))
                                        newPredicate.Rules.Add(unifyJ[key]);

                                    else
                                        newPredicate.Rules.Add(pred.Rules[i]);
                                }

                                cJSentence.Predicates.Add(newPredicate);
                            }
                        }

                        newSentence.Predicates.AddRange(cISentence.Predicates);
                        newSentence.Predicates.AddRange(cJSentence.Predicates);
                        resolvedSentence = true;
                        break;
                    }
                }

                if (resolvedSentence) {
                    solutionPath.Add(Ci.ToString() + " [and] " + Cj.ToString() + " -> " + newSentence.ToString());
                    break;
                }
            }

            // Factor out duplicates if they exist.
            //Factoring(newSentence);

            return (resolvedSentence) ? newSentence : null;
        }
Ejemplo n.º 4
0
        private bool Visited(Sentence a, Sentence b)
        {
            for (int i = 0; i < visited.Count(); ++i) {
                if ((a.ToString() == visited[i][0, 0].ToString() && b.ToString() == visited[i][0, 1].ToString()) || (b.ToString() == visited[i][0, 0].ToString() && a.ToString() == visited[i][0, 1].ToString())) {
                    return true;
                }
            }

            return false;
        }
Ejemplo n.º 5
0
        /// <summary>
        /// The resulting clause should only contain one copy of each literal. Factoring is the process
        /// of removing multiple copies. That is the function of this method.
        /// </summary>
        /// <param name="sentence"> The sentence to check for duplicates. </param>
        private void Factoring(Sentence sentence)
        {
            bool duplicates = false;

            if (duplicates)
                sentence.Predicates.Distinct().ToList();
        }