/// <summary>
/// Private helper for BDD construction.
/// </summary>
/// <param name="ft">
/// The ft.
/// </param>
/// <param name="nodeFactory">
/// The node factory.
/// </param>
/// <returns>
/// The <see cref="BDDNode"/>.
/// </returns>
private BDDNode CreateBDD(FaultTree.FaultTree ft, BDDNodeFactory nodeFactory)
{
int nextVariable = ft.Reduce(new MinTerminalTransformer());
if (nextVariable == int.MaxValue)
{
// ft should consist of only terminal node
return(nodeFactory.CreateNode(((FaultTreeLiteralNode)ft.Root).Value));
}
FaultTree.FaultTree high = ft.DeepCopy().Replace(nextVariable, true).Simplify();
FaultTree.FaultTree low = ft.DeepCopy().Replace(nextVariable, false).Simplify();
BDDNode highNode = this.CreateBDD(high, nodeFactory);
BDDNode lowNode = this.CreateBDD(low, nodeFactory);
return(nodeFactory.CreateNode(nextVariable, highNode, lowNode));
}
public static int NextId(this FaultTree.FaultTree ft)
{
return(ft.Reduce(new FaultTreeMaxIdTransformer()) + 1);
}
public static int NextBasicEvent(this FaultTree.FaultTree ft)
{
return(ft.Reduce(new MaxTerminalTransformer()) + 1);
}