|
public getAssignedSymbols ( ) : ReadOnlyCollection |
||
| return | ReadOnlyCollection |
|
private SymbolValuePair findUnitClause(List <Sentence> clauseList, Model model,
List <Symbol> symbols)
{
for (int i = 0; i < clauseList.Count; i++)
{
Sentence clause = (Sentence)clauseList[i];
if ((clause is Symbol) &&
(!(model.getAssignedSymbols().Contains(clause))))
{
// System.Console.WriteLine("found unit clause - assigning");
return(new SymbolValuePair(new Symbol(((Symbol)clause)
.getValue()), true));
}
if (clause is UnarySentence)
{
UnarySentence sentence = (UnarySentence)clause;
Sentence negated = sentence.getNegated();
if ((negated is Symbol) &&
(!(model.getAssignedSymbols().Contains(negated))))
{
// System.Console.WriteLine("found unit clause type 2 -
// assigning");
return(new SymbolValuePair(new Symbol(((Symbol)negated)
.getValue()), false));
}
}
}
return(new SymbolValuePair());// failed to find any unit clause;
}
public SymbolValuePair findPureSymbolValuePair(List<Sentence> clauseList,
Model model, List<Symbol> symbols)
{
List<Sentence> _clausesWithNonTrueValues = clausesWithNonTrueValues(clauseList,
model);
Sentence nonTrueClauses = LogicUtils.chainWith("AND",
_clausesWithNonTrueValues);
// System.Console.WriteLine("Unsatisfied clauses = "
// + clausesWithNonTrueValues.Count);
List<Symbol> symbolsAlreadyAssigned = new List<Symbol>( model.getAssignedSymbols());
// debug
// List symList = asList(symbolsAlreadyAssigned);
//
// System.Console.WriteLine(" assignedSymbols = " + symList.Count);
// if (symList.Count == 52) {
// System.Console.WriteLine("untrue clauses = " + clausesWithNonTrueValues);
// System.Console.WriteLine("model= " + model);
// }
// debug
List<Symbol> purePositiveSymbols = SetOps
.difference(new SymbolClassifier()
.getPurePositiveSymbolsIn(nonTrueClauses),
symbolsAlreadyAssigned);
List<Symbol> pureNegativeSymbols = SetOps
.difference(new SymbolClassifier()
.getPureNegativeSymbolsIn(nonTrueClauses),
symbolsAlreadyAssigned);
// if none found return "not found
if ((purePositiveSymbols.Count == 0)
&& (pureNegativeSymbols.Count == 0))
{
return new SymbolValuePair();// automatically set to null values
}
else
{
if (purePositiveSymbols.Count > 0)
{
Symbol symbol =purePositiveSymbols[0];
if (pureNegativeSymbols.Contains(symbol))
{
throw new ApplicationException("Symbol " + symbol.getValue()
+ "misclassified");
}
return new SymbolValuePair(symbol, true);
}
else
{
Symbol symbol = new Symbol((pureNegativeSymbols[0])
.getValue());
if (purePositiveSymbols.Contains(symbol))
{
throw new ApplicationException("Symbol " + symbol.getValue()
+ "misclassified");
}
return new SymbolValuePair(symbol, false);
}
}
}
private SymbolValuePair findUnitClause(List<Sentence> clauseList, Model model,
List<Symbol> symbols)
{
for (int i = 0; i < clauseList.Count; i++)
{
Sentence clause = (Sentence)clauseList[i];
if ((clause is Symbol)
&& (!(model.getAssignedSymbols().Contains(clause))))
{
// System.Console.WriteLine("found unit clause - assigning");
return new SymbolValuePair(new Symbol(((Symbol)clause)
.getValue()), true);
}
if (clause is UnarySentence)
{
UnarySentence sentence = (UnarySentence)clause;
Sentence negated = sentence.getNegated();
if ((negated is Symbol)
&& (!(model.getAssignedSymbols().Contains(negated))))
{
// System.Console.WriteLine("found unit clause type 2 -
// assigning");
return new SymbolValuePair(new Symbol(((Symbol)negated)
.getValue()), false);
}
}
}
return new SymbolValuePair();// failed to find any unit clause;
}
public SymbolValuePair findPureSymbolValuePair(List <Sentence> clauseList,
Model model, List <Symbol> symbols)
{
List <Sentence> _clausesWithNonTrueValues = clausesWithNonTrueValues(clauseList,
model);
Sentence nonTrueClauses = LogicUtils.chainWith("AND",
_clausesWithNonTrueValues);
// System.Console.WriteLine("Unsatisfied clauses = "
// + clausesWithNonTrueValues.Count);
List <Symbol> symbolsAlreadyAssigned = new List <Symbol>(model.getAssignedSymbols());
// debug
// List symList = asList(symbolsAlreadyAssigned);
//
// System.Console.WriteLine(" assignedSymbols = " + symList.Count);
// if (symList.Count == 52) {
// System.Console.WriteLine("untrue clauses = " + clausesWithNonTrueValues);
// System.Console.WriteLine("model= " + model);
// }
// debug
List <Symbol> purePositiveSymbols = SetOps
.difference(new SymbolClassifier()
.getPurePositiveSymbolsIn(nonTrueClauses),
symbolsAlreadyAssigned);
List <Symbol> pureNegativeSymbols = SetOps
.difference(new SymbolClassifier()
.getPureNegativeSymbolsIn(nonTrueClauses),
symbolsAlreadyAssigned);
// if none found return "not found
if ((purePositiveSymbols.Count == 0) &&
(pureNegativeSymbols.Count == 0))
{
return(new SymbolValuePair());// automatically set to null values
}
else
{
if (purePositiveSymbols.Count > 0)
{
Symbol symbol = purePositiveSymbols[0];
if (pureNegativeSymbols.Contains(symbol))
{
throw new ApplicationException("Symbol " + symbol.getValue()
+ "misclassified");
}
return(new SymbolValuePair(symbol, true));
}
else
{
Symbol symbol = new Symbol((pureNegativeSymbols[0])
.getValue());
if (purePositiveSymbols.Contains(symbol))
{
throw new ApplicationException("Symbol " + symbol.getValue()
+ "misclassified");
}
return(new SymbolValuePair(symbol, false));
}
}
}
