public bool AskWithDpll(String queryString)
{
Sentence query = null, cnfForm = null;
//TODO: figure out if we really need to eat the exception here, if so add debug compilation condition
try {
// just a check to see that the query is well formed
query = (Sentence)parser.Parse(queryString);
} catch (Exception e) {
Debug.WriteLine("error parsing query" + e.Message);
}
Sentence kbSentence = this.AsSentence();
Sentence kbPlusQuery = null;
if (kbSentence != null)
{
kbPlusQuery = (Sentence)parser.Parse(" ( " + kbSentence + " AND " + queryString + " )");
}
else
{
kbPlusQuery = query;
}
try {
cnfForm = new CNFTransformer().Transform(kbPlusQuery);
// System.out.println(cnfForm.toString());
} catch (Exception e) {
Debug.WriteLine("error converting kb + query to CNF" + e.Message);
}
return(new DPLL().DPLLSatisfiable(cnfForm));
}
public Model FindModelFor(String logicalSentence, int numberOfFlips,
double probabilityOfRandomWalk)
{
this.myModel = new Model();
var s = (Sentence) new PEParser().Parse(logicalSentence);
var transformer = new CNFTransformer();
var clauseGatherer = new CNFClauseGatherer();
var sc = new SymbolCollector();
var symbols = sc.GetSymbolsIn(s).ToList();
var r = new Random();
foreach (var sym in symbols)
{
this.myModel = this.myModel.Extend(sym, Util.RandomBoolean());
}
IList <Sentence> clauses = clauseGatherer.GetClausesFrom(transformer.Transform(s)).ToList();
//IList<Sentence> ClauseSet = new Converter<Sentence>().ListToSet(clauses);
lastClauses = clauses;
lastClausesFlip = new List <Int64>(clauses.Count + 1);
for (int i = 0; i < clauses.Count; i++)
{
lastClausesFlip.Add(0);
}
for (int i = 0; i < numberOfFlips; i++)
{
List <int> unsatList = new List <int>();
int numSat = this.GetNumberOfClausesSatisfiedIn(new Converter <Sentence>().ListToSet(clauses), myModel, unsatList);
if (numSat == clauses.Count)
{
trials = i;
return(myModel);
}
int probe = FindAnRandomUnsatisfiedClause(clauses, myModel, unsatList);
//Sentence clause = clauses[random.Next(clauses.Count)];
Sentence clause = clauses[probe];
lastClausesFlip[probe]++;
IList <Symbol> symbolsInClause = sc.GetSymbolsIn(clause).ToList();
if (random.NextDouble() >= probabilityOfRandomWalk)
{
Symbol randomSymbol = symbolsInClause[random.Next(symbolsInClause.Count)];
myModel = myModel.Flip(randomSymbol);
}
else
{
Symbol symbolToFlip = this.GetSymbolWhoseFlipMaximisesSatisfiedClauses(
new Converter <Sentence>().ListToSet(clauses),
symbolsInClause, myModel);
myModel = myModel.Flip(symbolToFlip);
}
}
trials = numberOfFlips;
return(null);
}
public void testAimaExample()
{
Sentence aimaEg = (Sentence)parser.parse("( B11 <=> (P12 OR P21))");
CNFTransformer transformer = new CNFTransformer();
Sentence transformed = transformer.transform(aimaEg);
List <Sentence> clauses = gatherer.getClausesFrom(transformed);
Sentence clause1 = (Sentence)parser.parse("( B11 OR ( NOT P12 ) )");
Sentence clause2 = (Sentence)parser.parse("( B11 OR ( NOT P21 ) )");
Sentence clause3 = (Sentence)parser
.parse("( ( NOT B11 ) OR ( P12 OR P21 ) )");
Assert.AreEqual(3, clauses.Count);
Assert.IsTrue(clauses.Contains(clause1));
Assert.IsTrue(clauses.Contains(clause2));
Assert.IsTrue(clauses.Contains(clause3));
}
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 = sc.getSymbolsIn(s);
Random r = new Random();
for (int i = 0; i < symbols.Count; i++)
{
Symbol sym = (Symbol)symbols[i];
myModel = myModel.extend(sym, Util.randombool());
}
List <Sentence> clauses = clauseGatherer.getClausesFrom(transformer
.transform(s));
for (int i = 0; i < numberOfFlips; i++)
{
if (getNumberOfClausesSatisfiedIn(clauses, myModel) == clauses.Count)
{
return(myModel);
}
Sentence clause = clauses[random.Next(clauses.Count)];
List <Symbol> symbolsInClause = sc
.getSymbolsIn(clause);
if (random.NextDouble() >= probabilityOfRandomWalk)
{
Symbol randomSymbol = symbolsInClause[random
.Next(symbolsInClause.Count)];
myModel = myModel.flip(randomSymbol);
}
else
{
Symbol symbolToFlip = getSymbolWhoseFlipMaximisesSatisfiedClauses(
clauses,
symbolsInClause, myModel);
myModel = myModel.flip(symbolToFlip);
}
}
return(null);
}
public bool askWithDpll(String queryString)
{
Sentence query = null, cnfForm = null;
try
{
// just a check to see that the query is well formed
query = (Sentence)parser.parse(queryString);
}
catch (Exception e)
{
System.Console.WriteLine("error parsing query" + e);
}
Sentence kbSentence = asSentence();
Sentence kbPlusQuery = null;
if (kbSentence != null)
{
kbPlusQuery = (Sentence)parser.parse(" ( " + kbSentence.ToString()
+ " AND (NOT " + queryString + " ))");
}
else
{
kbPlusQuery = query;
}
try
{
cnfForm = new CNFTransformer().transform(kbPlusQuery);
// System.Console.WriteLine(cnfForm.ToString());
}
catch (Exception e)
{
System.Console.WriteLine("error converting kb + query to CNF "
+ e);
}
return(!new DPLL().dpllSatisfiable(cnfForm));
}
public void setUp()
{
transformer = new CNFTransformer();
}
