/// <summary>
/// Generate the counter example for LTL model checking, including 2 parts: prefix, and period.
/// [ REFS: '', DEREFS: automataBDD.transitionBDD, this.prefix, this.period ]
/// </summary>
/// <param name="automataBDD"></param>
/// <param name="encoder"></param>
/// <returns></returns>
public void GetMCResult(AutomataBDD automataBDD, BDDEncoder encoder)
{
VerificationOutput.CounterExampleTrace.Add(InitialStep);
if (VerificationOutput.VerificationResult == VerificationResultType.INVALID && VerificationOutput.GenerateCounterExample)
{
VerificationOutput.LoopIndex = this.prefix.Count + 1;
List <CUDDNode> traces = new List <CUDDNode>();
ExpressionBDDEncoding initEncoding = automataBDD.initExpression.TranslateBoolExpToBDD(encoder.model);
traces.Add(CUDD.Function.Or(initEncoding.GuardDDs));
traces.AddRange(this.prefix);
traces.AddRange(this.period);
Valuation currentValuation = this.InitialStep.GlobalEnv;
Valuation lastValuation;
for (int i = 1; i < traces.Count; i++)
{
//Get event information
CUDD.Ref(traces[i], traces[i - 1]);
CUDDNode transitionTemp = CUDD.Function.And(traces[i - 1], encoder.model.SwapRowColVars(traces[i]));
CUDD.Ref(automataBDD.transitionBDD);
CUDDNode transWithEventInfo = CUDD.Function.And(transitionTemp, automataBDD.transitionBDD);
transWithEventInfo = CUDD.Abstract.ThereExists(transWithEventInfo, encoder.model.AllRowVarsExceptSingleCopy);
transWithEventInfo = CUDD.RestrictToFirst(transWithEventInfo, encoder.model.AllColVars);
lastValuation = currentValuation;
currentValuation = encoder.GetValuationFromBDD(transWithEventInfo, this.InitialStep.GlobalEnv);
string eventName = encoder.GetEventChannelName(lastValuation, currentValuation, transWithEventInfo);
VerificationOutput.CounterExampleTrace.Add(new ConfigurationBDD(eventName, currentValuation));
//
CUDD.Deref(transWithEventInfo);
}
//
CUDD.Deref(traces);
}
CUDD.Deref(automataBDD.transitionBDD);
VerificationOutput.ActualMemoryUsage = CUDD.ReadMemoryInUse();
VerificationOutput.numberOfBoolVars = encoder.model.NumberOfBoolVars;
encoder.model.Close();
}
