public override ISet <Clause> visitBinarySentence(ComplexSentence s, ISet <Clause> arg)
{
if (s.isAndSentence())
{
s.getSimplerSentence(0).accept(this, arg);
s.getSimplerSentence(1).accept(this, arg);
}
else if (s.isOrSentence())
{
ICollection <Literal> literals = CollectionFactory.CreateQueue <Literal>(LiteralCollector.getLiterals(s));
arg.Add(new Clause(literals));
}
else
{
throw new IllegalArgumentException("Sentence is not in CNF: " + s);
}
return(arg);
}
public override Sentence visitBinarySentence(ComplexSentence s, object arg)
{
Sentence result = null;
if (s.isAndSentence())
{
Sentence s1 = s.getSimplerSentence(0).accept(this, arg);
Sentence s2 = s.getSimplerSentence(1).accept(this, arg);
if (s1.isOrSentence() || s2.isOrSentence())
{
Sentence alpha, betaAndGamma;
if (s2.isOrSentence())
{
// (α & (β | γ))
// Note: even if both are 'or' sentence
// we will prefer to use s2
alpha = s1;
betaAndGamma = s2;
}
else
{
// Note: Need to handle this case too
// ((β | γ) & α)
alpha = s2;
betaAndGamma = s1;
}
Sentence beta = betaAndGamma.getSimplerSentence(0);
Sentence gamma = betaAndGamma.getSimplerSentence(1);
if (s2.isOrSentence())
{
// ((α & β) | (α & γ))
Sentence alphaAndBeta = (new ComplexSentence(Connective.AND,
alpha, beta)).accept(this, null);
Sentence alphaAndGamma = (new ComplexSentence(Connective.AND,
alpha, gamma)).accept(this, null);
result = new ComplexSentence(Connective.OR, alphaAndBeta,
alphaAndGamma);
}
else
{
// ((β & α) | (γ & α))
Sentence betaAndAlpha = (new ComplexSentence(Connective.AND,
beta, alpha)).accept(this, null);
Sentence gammaAndAlpha = (new ComplexSentence(Connective.AND,
gamma, alpha)).accept(this, null);
result = new ComplexSentence(Connective.OR, betaAndAlpha,
gammaAndAlpha);
}
}
else
{
result = new ComplexSentence(Connective.AND, s1, s2);
}
}
else
{
result = base.visitBinarySentence(s, arg);
}
return(result);
}