public bool UniversalQuantifierRule(ref DerivationStep s)
{
List <Node> temp = s.GetFormulas().ToList();
foreach (var n in s.GetFormulas())
{
if (n is Universal u)
{
Universal newUniversal = FunctionHelper.DeepClone <Universal>(u);
if (newUniversal.ReplaceChecked() == true)
{
continue;
}
DerivationStep newStep = new DerivationStep(s.GetActiveVariables());
newUniversal.SetSubtitution();
foreach (var v in newStep.GetActiveVariables())
{
Node addNode = FunctionHelper.DeepClone <Node>(newUniversal.RightNode);
this.ChangeVarHelperUni(addNode, v);
newStep.AddFormulas(addNode);
}
newStep.AddFormulas(newUniversal);
newStep.Merge(temp);
s.RightNode = newStep;
this._branchingPoint.Push(s.RightNode);
return(true);
}
else if (n is Negation && n.RightNode is Existential e)
{
Existential newExist = FunctionHelper.DeepClone <Existential>(e);
if (newExist.ReplaceChecked() == true)
{
continue;
}
DerivationStep newStep = new DerivationStep(s.GetActiveVariables());
newExist.SetSubtitution();
foreach (var v in newStep.GetActiveVariables())
{
Node addNode = FunctionHelper.DeepClone <Node>(newExist.RightNode);
this.ChangeVarHelperUni(addNode, v);
newStep.AddFormulas(new Negation("~", addNode));
}
newStep.AddFormulas(new Negation("~", newExist));
newStep.Merge(temp);
s.RightNode = newStep;
this._branchingPoint.Push(s.RightNode);
return(true);
}
}
return(false);
}
