private static List <List <Assignment> > EvaluateLogicalExpression(ParseTreeFOL_O expression, string[] subwords, string body)
{
if (expression.getTerm() != null)
{
Term term = expression.getTerm();
string[] freeVars = FOLSearcher.GetFreeVars(term);
return(TopDownFOLEvaluator.evaluateParsedExpression(term, subwords, freeVars, body));
}
else
{
List <List <Assignment> > leftTable = EvaluateLogicalExpression(expression.getLeftChild(), subwords, body);
List <List <Assignment> > rightTable = EvaluateLogicalExpression(expression.getRightChild(), subwords, body);
rightTable = FillInSolutions(rightTable, leftTable, subwords);
leftTable = FillInSolutions(leftTable, rightTable, subwords);
if (expression.getFolOperator() == FOLOperator.Disjunction)
{
leftTable.AddRange(rightTable.Where(r => !leftTable.Any(l => CompareSolutions(l, r))));
}
else
{
leftTable.RemoveAll(l => !rightTable.Any(r => CompareSolutions(l, r)));
}
return(leftTable);
}
}
static List <List <Assignment> > FillInSolutions(List <List <Assignment> > left, List <List <Assignment> > right, string[] subwords)
{
string[] leftVars = FOLSearcher.GetFreeVars(left);
string[] rightVars = FOLSearcher.GetFreeVars(right);
string[] newLeftVars = rightVars.Where(r => !leftVars.Any(l => r == l)).ToArray();
return(FillInSolutions(left, newLeftVars, subwords));
}