public TokenTree restrainNegation()
{
bool somethingDone;
do {
somethingDone = false;
List<Token> tokens = ReverseBFS();
foreach (Token t in tokens)
{
if (t is Negation && t.getChild(0).isFinal() == false)
{
Token t_parent = t.parent;
Token c = t.getChild(0);
if(c is Negation)
{
somethingDone = true;
if (t_parent == null)
root = c.getChild(0);
else
t_parent.setChild(t.indexInParent, c.getChild(0));
// Console.WriteLine(serialize());
}
else if(c is Operator)
{
somethingDone = true;
if (c.name == "AND")
{
Token n = new Operator(name: "OR");
Token left = c.getChild(0);
Token right = c.getChild(1);
Token newLeft = new Negation();
Token newRight = new Negation();
newLeft.setChild(0, left.Clone());
newRight.setChild(0, right.Clone());
n.setChild(0, newLeft);
n.setChild(1, newRight);
if (t_parent == null)
{
root = n;
}
else
{
t_parent.setChild(t.indexInParent, n);
}
//Console.WriteLine(serialize());
}
else if (c.name == "OR")
{
Token n = new Operator(name: "AND");
Token left = c.getChild(0);
Token right = c.getChild(1);
Token newLeft = new Negation();
Token newRight = new Negation();
newLeft.setChild(0, left.Clone());
newRight.setChild(0, right.Clone());
n.setChild(0, newLeft);
n.setChild(1, newRight);
if (t_parent == null)
{
root = n;
}
else
{
t_parent.setChild(t.indexInParent, n);
}
//Console.WriteLine(serialize());
}
}
else if(c is Quantifier)
{
somethingDone = true;
if (c.name == "FORALL")
{
Token n = new Quantifier(name: "EXISTS");
Token left = c.getChild(0);
Token right = c.getChild(1);
Token newRight = new Negation();
newRight.setChild(0, right.Clone());
n.setChild(0, left);
n.setChild(1, newRight);
if (t_parent == null)
{
root = n;
}
else
{
t_parent.setChild(t.indexInParent, n);
}
} else if (c.name == "EXISTS")
{
Token n = new Quantifier(name: "FORALL");
Token left = c.getChild(0);
Token right = c.getChild(1);
Token newRight = new Negation();
newRight.setChild(0, right.Clone());
n.setChild(0, left);
n.setChild(1, newRight);
if (t_parent == null)
{
root = n;
}
else
{
t_parent.setChild(t.indexInParent, n);
}
}
}
}
}
} while (somethingDone);
return this;
}
public TokenTree replaceImplies()
{
List<Token> tokens = ReverseBFS();
foreach (Token t in tokens)
{
if (t is Operator && t.name == "IMPLIES")
{
Token parent = t.parent;
Token left = t.getChild(0);
Token right = t.getChild(1);
Token n = new Operator(name: "OR");
Token newLeft = new Negation();
newLeft.setChild(0, left.Clone());
n.setChild(0, newLeft);
n.setChild(1, right.Clone());
if (parent == null)
{
root = n;
}
else
{
parent.setChild(t.indexInParent, n);
}
}
}
return this;
}