private void FactFlow(ILogicNode startNode)
{
if (startNode is ILiteralNode && _graph.OutDegree(startNode) == 1)
{
foreach (var node in _graph.Outgoing(startNode).Where(node => !node.Fact))
{
if (node is ILiteralNode)
{
var negNode = _graph.GetNode(Negate(node.Id));
if (negNode.Fact)
{
throw new Exception("KB is inconsistent, " + node.Id + " and " + negNode.Id + " are both facts!");
}
}
node.Fact = true;
FactFlow(node);
}
}
foreach (var node in _graph.Incoming(startNode).Where(node => !node.Fact))
{
if (node is IClauseNode)
{
if (_graph.Outgoing(node).All(dependency => dependency.Fact))
{
node.Fact = true;
FactFlow(node);
}
}
else if (node is ILiteralNode && (_graph.OutDegree(node) == 1 || node.Id.Contains("|")))
{
var negNode = _graph.GetNode(Negate(node.Id));
if (negNode.Fact)
{
throw new Exception("KB is inconsistent, " + node.Id + " and " + negNode.Id + " are both facts!");
}
node.Fact = true;
FactFlow(node);
}
}
}
