public bool PlfcEntails(KnowledgeBase kb, Symbol q)
{
IList <HornClause> hornClauses = this.AsHornClauses(kb.Sentences);
while (agenda.Count != 0)
{
Symbol p = agenda.Pop();
while (!this.GetInferred(p))
{
this.inferred[p] = true;
foreach (HornClause hornClause in
hornClauses.Where(hornClause => hornClause.PremisesContainsSymbol(p)))
{
this.DecrementCount(hornClause);
if (!this.CountIsZero(hornClause))
{
continue;
}
if (hornClause.Head.Equals(q))
{
return(true);
}
this.agenda.Push(hornClause.Head);
}
}
}
return(false);
}
//TODO: create a better name
public bool PlResolution(string kbs, string alphaString)
{
KnowledgeBase kb = new KnowledgeBase();
kb.Tell(kbs);
Sentence alpha = (Sentence) new PEParser().Parse(alphaString);
return(this.PlResolution(kb, alpha));
}
//TODO: Update this method with better name
public bool TtEntails(KnowledgeBase kb, String alpha)
{
Sentence kbSentence = kb.AsSentence();
Sentence querySentence = (Sentence) new PEParser().Parse(alpha);
SymbolCollector collector = new SymbolCollector();
ISet <Symbol> kbSymbols = collector.GetSymbolsIn(kbSentence);
ISet <Symbol> querySymbols = collector.GetSymbolsIn(querySentence);
IList <Symbol> symbolList = kbSymbols.Union(querySymbols).ToList();
return(ttCheckAll(kbSentence, querySentence, symbolList, new Model()));
}
public Sentence AsSentence()
{
ISet <Symbol> Asyms = GetAssignedSymbols();
KnowledgeBase tempKB = new KnowledgeBase();
if (Asyms == null)
{
Console.WriteLine("ERR: AsSentence() Asyms is null!!!");
}
else
{
Console.WriteLine("DBG: Asyms.Count={0}", Asyms.Count);
}
foreach (Symbol k in Asyms)
{
try
{
if (IsTrue(k))
{
tempKB.Tell("(" + k.Value + ")");
}
else
{
tempKB.Tell("(NOT " + k.Value + ")");
}
}
catch (Exception e)
{
Console.WriteLine("ERR: AsSentence() ", e.Message, e.StackTrace);
}
}
if (tempKB.Size() == 0)
{
Console.WriteLine("ERR: AsSentence() tempKB.Size==0");
}
return(tempKB.AsSentence());
}
public bool PlResolution(KnowledgeBase kb, Sentence alpha)
{
Sentence kBAndNotAlpha = new BinarySentence("AND", kb.AsSentence(),
new UnarySentence(alpha));
IList <Sentence> clauses = new CNFClauseGatherer()
.GetClausesFrom(new CNFTransformer().Transform(kBAndNotAlpha)).ToList();
clauses = this.FilterOutClausesWithTwoComplementaryLiterals(clauses);
var newClauses = new List <Sentence>();
while (true)
{
IList <IList <Sentence> > pairs = this.GetCombinationPairs(clauses.ToList());
for (int i = 0; i < pairs.Count; i++)
{
IList <Sentence> pair = pairs[i];
// System.out.println("pair number" + i+" of "+pairs.Count);
IList <Sentence> resolvents = this.PLResolve(pair[0], pair[1]);
resolvents = this.FilterOutClausesWithTwoComplementaryLiterals(resolvents);
if (resolvents.Contains(new Symbol("EMPTY_CLAUSE")))
{
return(true);
}
newClauses = newClauses.Union(resolvents).ToList();
// System.out.println("clauseslist size = " +clauses.Count);
}
if (newClauses.Intersect(clauses).Count() == newClauses.Count)
{// subset test
return(false);
}
clauses = newClauses.Union(clauses).ToList();
clauses = this.FilterOutClausesWithTwoComplementaryLiterals(clauses);
}
}
public bool PlResolution(KnowledgeBase kb, string alpha)
{
return(this.PlResolution(kb, (Sentence) new PEParser().Parse(alpha)));
}
//TODO: update with better name
public bool PlfcEntails(KnowledgeBase kb, string s)
{
return(this.PlfcEntails(kb, new Symbol(s)));
}
