Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisAlleleFrequencyAnalyzer.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisAlleleFrequencyAnalyzer.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisAlleleFrequencyAnalyzer.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
@@ -75,5 +75,4 @@
     public static Allele[] CalculateAlleles(ISymbolicExpressionTree solution, int alleleTreedepth) {
       return GetAllSubtreesOfDepth(solution, alleleTreedepth)
-        .AsParallel()
         .Select(t => GetAlleleFromSubtreeOfDepth(t, alleleTreedepth))
         .ToArray();
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisAnalyzer.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisAnalyzer.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisAnalyzer.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisMultiObjectiveAnalyzer.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisMultiObjectiveAnalyzer.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisMultiObjectiveAnalyzer.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisMultiObjectiveTrainingBestSolutionAnalyzer.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisMultiObjectiveTrainingBestSolutionAnalyzer.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisMultiObjectiveTrainingBestSolutionAnalyzer.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisMultiObjectiveValidationAnalyzer.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisMultiObjectiveValidationAnalyzer.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisMultiObjectiveValidationAnalyzer.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisMultiObjectiveValidationBestSolutionAnalyzer.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisMultiObjectiveValidationBestSolutionAnalyzer.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisMultiObjectiveValidationBestSolutionAnalyzer.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
@@ -121,5 +121,4 @@
 
       var qualities = tree
-        .AsParallel()
         .Select(t => evaluator.Evaluate(childContext, t, problemData, rows))
         .ToArray();
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisSingleObjectiveAnalyzer.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisSingleObjectiveAnalyzer.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisSingleObjectiveAnalyzer.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisSingleObjectivePruningAnalyzer.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisSingleObjectivePruningAnalyzer.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisSingleObjectivePruningAnalyzer.cs	(revision 11208)
@@ -1,3 +1,26 @@
-﻿using System;
+﻿#region License Information
+
+/* HeuristicLab
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ *
+ * This file is part of HeuristicLab.
+ *
+ * HeuristicLab is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * HeuristicLab is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#endregion
+
+using System;
 using System.Linq;
 using HeuristicLab.Analysis;
@@ -27,5 +50,7 @@
     private const string PruningOperatorParameterName = "PruningOperator";
     private const string ResultsParameterName = "Results";
-    #endregion
+    private const string PopulationSizeParameterName = "PopulationSize";
+    #endregion
+
     #region private members
     private DataReducer prunedSubtreesReducer;
@@ -33,6 +58,6 @@
     private DataTableValuesCollector valuesCollector;
     private ResultsCollector resultsCollector;
-    private EmptyOperator emptyOp;
-    #endregion
+    #endregion
+
     #region parameter properties
     public IValueParameter<SymbolicDataAnalysisExpressionPruningOperator> PruningOperatorParameter {
@@ -48,39 +73,63 @@
       get { return (ILookupParameter<IRandom>)Parameters[RandomParameterName]; }
     }
-    private ILookupParameter<IDataAnalysisProblemData> ProblemDataParameter {
-      get { return (ILookupParameter<IDataAnalysisProblemData>)Parameters[ProblemDataParameterName]; }
-    }
-    public IValueParameter<IntValue> UpdateIntervalParameter {
-      get { return (IValueParameter<IntValue>)Parameters[UpdateIntervalParameterName]; }
-    }
-    public IValueParameter<IntValue> UpdateCounterParameter {
-      get { return (IValueParameter<IntValue>)Parameters[UpdateCounterParameterName]; }
-    }
-    public IValueParameter<DoubleRange> PopulationSliceParameter {
-      get { return (IValueParameter<DoubleRange>)Parameters[PopulationSliceParameterName]; }
-    }
-    public IValueParameter<DoubleValue> PruningProbabilityParameter {
-      get { return (IValueParameter<DoubleValue>)Parameters[PruningProbabilityParameterName]; }
-    }
-    #endregion
+    public IFixedValueParameter<IntValue> UpdateIntervalParameter {
+      get { return (IFixedValueParameter<IntValue>)Parameters[UpdateIntervalParameterName]; }
+    }
+    public IFixedValueParameter<IntValue> UpdateCounterParameter {
+      get { return (IFixedValueParameter<IntValue>)Parameters[UpdateCounterParameterName]; }
+    }
+    public IFixedValueParameter<DoubleRange> PopulationSliceParameter {
+      get { return (IFixedValueParameter<DoubleRange>)Parameters[PopulationSliceParameterName]; }
+    }
+    public IFixedValueParameter<DoubleValue> PruningProbabilityParameter {
+      get { return (IFixedValueParameter<DoubleValue>)Parameters[PruningProbabilityParameterName]; }
+    }
+    public ILookupParameter<IntValue> PopulationSizeParameter {
+      get { return (ILookupParameter<IntValue>)Parameters[PopulationSizeParameterName]; }
+    }
+    #endregion
+
     #region properties
     protected SymbolicDataAnalysisExpressionPruningOperator PruningOperator { get { return PruningOperatorParameter.Value; } }
-    protected IDataAnalysisProblemData ProblemData { get { return ProblemDataParameter.ActualValue; } }
-    protected IntValue UpdateInterval { get { return UpdateIntervalParameter.Value; } }
-    protected IntValue UpdateCounter { get { return UpdateCounterParameter.Value; } }
-    protected DoubleRange PopulationSlice { get { return PopulationSliceParameter.Value; } }
-    protected DoubleValue PruningProbability { get { return PruningProbabilityParameter.Value; } }
-    protected IRandom Random { get { return RandomParameter.ActualValue; } }
-    protected DoubleValue NodeImpactThreshold { get { return NodeImpactThresholdParameter.Value; } }
-    protected BoolValue PruneOnlyZeroImpactNodes { get { return PruneOnlyZeroImpactNodesParameter.Value; } }
-    #endregion
+    protected int UpdateInterval { get { return UpdateIntervalParameter.Value.Value; } }
+
+    protected int UpdateCounter {
+      get { return UpdateCounterParameter.Value.Value; }
+      set { UpdateCounterParameter.Value.Value = value; }
+    }
+
+    protected double PopulationSliceStart {
+      get { return PopulationSliceParameter.Value.Start; }
+      set { PopulationSliceParameter.Value.Start = value; }
+    }
+
+    protected double PopulationSliceEnd {
+      get { return PopulationSliceParameter.Value.End; }
+      set { PopulationSliceParameter.Value.End = value; }
+    }
+
+    protected double PruningProbability {
+      get { return PruningProbabilityParameter.Value.Value; }
+      set { PruningProbabilityParameter.Value.Value = value; }
+    }
+
+    protected bool PruneOnlyZeroImpactNodes {
+      get { return PruneOnlyZeroImpactNodesParameter.Value.Value; }
+      set { PruneOnlyZeroImpactNodesParameter.Value.Value = value; }
+    }
+    protected double NodeImpactThreshold {
+      get { return NodeImpactThresholdParameter.Value.Value; }
+      set { NodeImpactThresholdParameter.Value.Value = value; }
+    }
+    #endregion
+
     #region IStatefulItem members
     public override void InitializeState() {
       base.InitializeState();
-      UpdateCounter.Value = 0;
+      UpdateCounter = 0;
     }
     public override void ClearState() {
       base.ClearState();
-      UpdateCounter.Value = 0;
+      UpdateCounter = 0;
     }
     #endregion
@@ -88,4 +137,5 @@
     [StorableConstructor]
     protected SymbolicDataAnalysisSingleObjectivePruningAnalyzer(bool deserializing) : base(deserializing) { }
+
     protected SymbolicDataAnalysisSingleObjectivePruningAnalyzer(SymbolicDataAnalysisSingleObjectivePruningAnalyzer original, Cloner cloner)
       : base(original, cloner) {
@@ -99,15 +149,114 @@
         this.resultsCollector = (ResultsCollector)original.resultsCollector.Clone();
     }
+
+    [StorableHook(HookType.AfterDeserialization)]
+    private void AfterDeserialization() {
+      if (!Parameters.ContainsKey(PopulationSizeParameterName)) {
+        Parameters.Add(new LookupParameter<IntValue>(PopulationSizeParameterName, "The population of individuals."));
+      }
+      if (Parameters.ContainsKey(UpdateCounterParameterName)) {
+        var fixedValueParameter = Parameters[UpdateCounterParameterName] as FixedValueParameter<IntValue>;
+        if (fixedValueParameter == null) {
+          var valueParameter = (ValueParameter<IntValue>)Parameters[UpdateCounterParameterName];
+          Parameters.Remove(UpdateCounterParameterName);
+          Parameters.Add(new FixedValueParameter<IntValue>(UpdateCounterParameterName, valueParameter.Value));
+        }
+      }
+      if (Parameters.ContainsKey(UpdateIntervalParameterName)) {
+        var fixedValueParameter = Parameters[UpdateIntervalParameterName] as FixedValueParameter<IntValue>;
+        if (fixedValueParameter == null) {
+          var valueParameter = (ValueParameter<IntValue>)Parameters[UpdateIntervalParameterName];
+          Parameters.Remove(UpdateIntervalParameterName);
+          Parameters.Add(new FixedValueParameter<IntValue>(UpdateIntervalParameterName, valueParameter.Value));
+        }
+      }
+      if (Parameters.ContainsKey(PopulationSliceParameterName)) {
+        var fixedValueParameter = Parameters[PopulationSliceParameterName] as FixedValueParameter<DoubleRange>;
+        if (fixedValueParameter == null) {
+          var valueParameter = (ValueParameter<DoubleRange>)Parameters[PopulationSliceParameterName];
+          Parameters.Remove(PopulationSliceParameterName);
+          Parameters.Add(new FixedValueParameter<DoubleRange>(PopulationSliceParameterName, valueParameter.Value));
+        }
+      }
+      if (Parameters.ContainsKey(PruningProbabilityParameterName)) {
+        var fixedValueParameter = Parameters[PruningProbabilityParameterName] as FixedValueParameter<DoubleValue>;
+        if (fixedValueParameter == null) {
+          var valueParameter = (ValueParameter<DoubleValue>)Parameters[PruningProbabilityParameterName];
+          Parameters.Remove(PruningProbabilityParameterName);
+          Parameters.Add(new FixedValueParameter<DoubleValue>(PruningProbabilityParameterName, valueParameter.Value));
+        }
+      }
+    }
+
     protected SymbolicDataAnalysisSingleObjectivePruningAnalyzer() {
       #region add parameters
-      Parameters.Add(new ValueParameter<DoubleRange>(PopulationSliceParameterName, new DoubleRange(0.75, 1)));
-      Parameters.Add(new ValueParameter<DoubleValue>(PruningProbabilityParameterName, new DoubleValue(0.5)));
-      Parameters.Add(new ValueParameter<IntValue>(UpdateIntervalParameterName, "The interval in which the tree length analysis should be applied.", new IntValue(1)));
-      Parameters.Add(new ValueParameter<IntValue>(UpdateCounterParameterName, "The value which counts how many times the operator was called", new IntValue(0)));
-      Parameters.Add(new LookupParameter<IRandom>(RandomParameterName));
-      Parameters.Add(new LookupParameter<IDataAnalysisProblemData>(ProblemDataParameterName));
-      Parameters.Add(new FixedValueParameter<DoubleValue>(NodeImpactThresholdParameterName, new DoubleValue(0.0)));
-      Parameters.Add(new FixedValueParameter<BoolValue>(PruneOnlyZeroImpactNodesParameterName, new BoolValue(false)));
+      Parameters.Add(new FixedValueParameter<DoubleRange>(PopulationSliceParameterName, "The slice of the population where pruning should be applied.", new DoubleRange(0.75, 1)));
+      Parameters.Add(new FixedValueParameter<DoubleValue>(PruningProbabilityParameterName, "The probability for pruning an individual.", new DoubleValue(0.5)));
+      Parameters.Add(new FixedValueParameter<IntValue>(UpdateIntervalParameterName, "The interval in which the tree length analysis should be applied.", new IntValue(1)));
+      Parameters.Add(new FixedValueParameter<IntValue>(UpdateCounterParameterName, "The value which counts how many times the operator was called", new IntValue(0)));
+      Parameters.Add(new LookupParameter<IRandom>(RandomParameterName, "The random number generator."));
+      Parameters.Add(new LookupParameter<IDataAnalysisProblemData>(ProblemDataParameterName, "The problem data."));
+      Parameters.Add(new FixedValueParameter<DoubleValue>(NodeImpactThresholdParameterName, "The impact threshold  below which an individual should be pruned.", new DoubleValue(0.0)));
+      Parameters.Add(new FixedValueParameter<BoolValue>(PruneOnlyZeroImpactNodesParameterName, "Switch to determine of only zero impact individuals should be pruned.", new BoolValue(false)));
+      Parameters.Add(new LookupParameter<IntValue>(PopulationSizeParameterName, "The population of individuals."));
       #endregion
+    }
+
+    // 
+    /// <summary>
+    /// Computes the closed interval bounding the portion of the population that is to be pruned. 
+    /// </summary>
+    /// <returns>Returns an int range [start, end]</returns>
+    private IntRange GetSliceBounds() {
+      if (PopulationSliceStart < 0 || PopulationSliceEnd < 0) throw new ArgumentOutOfRangeException("The slice bounds cannot be negative.");
+      if (PopulationSliceStart > 1 || PopulationSliceEnd > 1) throw new ArgumentOutOfRangeException("The slice bounds should be expressed as unit percentages.");
+      var count = PopulationSizeParameter.ActualValue.Value;
+      var start = (int)Math.Round(PopulationSliceStart * count);
+      var end = (int)Math.Round(PopulationSliceEnd * count);
+      if (end > count) end = count;
+
+      if (start >= end) throw new ArgumentOutOfRangeException("Invalid PopulationSlice bounds.");
+      return new IntRange(start, end);
+    }
+
+    private IOperation CreatePruningOperation() {
+      var operations = new OperationCollection { Parallel = true };
+      var range = GetSliceBounds();
+      var qualities = Quality.Select(x => x.Value).ToArray();
+      var indices = Enumerable.Range(0, qualities.Length).ToArray();
+      Array.Sort(qualities, indices);
+      if (!Maximization.Value) Array.Reverse(indices);
+
+      var subscopes = ExecutionContext.Scope.SubScopes;
+      var random = RandomParameter.ActualValue;
+
+      var empty = new EmptyOperator();
+
+      for (int i = 0; i < subscopes.Count; ++i) {
+        IOperator @operator;
+        if (range.Start <= i && i < range.End && random.NextDouble() <= PruningProbability)
+          @operator = PruningOperator;
+        else @operator = empty;
+        var index = indices[i];
+        var subscope = subscopes[index];
+        operations.Add(ExecutionContext.CreateChildOperation(@operator, subscope));
+      }
+      return operations;
+    }
+
+    public override IOperation Apply() {
+      UpdateCounter++;
+      if (UpdateCounter != UpdateInterval) return base.Apply();
+      UpdateCounter = 0;
+
+      if (prunedSubtreesReducer == null || prunedTreesReducer == null || valuesCollector == null || resultsCollector == null) { InitializeOperators(); }
+
+      var prune = CreatePruningOperation();
+      var reducePrunedSubtrees = ExecutionContext.CreateChildOperation(prunedSubtreesReducer);
+      var reducePrunedTrees = ExecutionContext.CreateChildOperation(prunedTreesReducer);
+      var collectValues = ExecutionContext.CreateChildOperation(valuesCollector);
+      var collectResults = ExecutionContext.CreateChildOperation(resultsCollector);
+
+      return new OperationCollection { prune, reducePrunedSubtrees, reducePrunedTrees, collectValues, collectResults, base.Apply() };
     }
 
@@ -133,59 +282,4 @@
       resultsCollector.CollectedValues.Add(new LookupParameter<DataTable>("Population pruning"));
       resultsCollector.ResultsParameter.ActualName = ResultsParameterName;
-
-      emptyOp = new EmptyOperator();
-    }
-
-    // 
-    /// <summary>
-    /// Computes the closed interval bounding the portion of the population that is to be pruned. 
-    /// </summary>
-    /// <returns>Returns an int range [start, end]</returns>
-    private IntRange GetSliceBounds() {
-      var count = ExecutionContext.Scope.SubScopes.Count;
-      var start = (int)Math.Round(PopulationSlice.Start * count);
-      var end = (int)Math.Round(PopulationSlice.End * count);
-      if (end > count) end = count;
-
-      if (start >= end) throw new ArgumentOutOfRangeException("Invalid PopulationSlice bounds.");
-      return new IntRange(start, end);
-    }
-
-    private IOperation CreatePruningOperation() {
-      var oc = new OperationCollection { Parallel = true };
-      var range = GetSliceBounds();
-      var qualities = Quality.Select(x => x.Value).ToArray();
-      var indices = Enumerable.Range(0, qualities.Length).ToArray();
-      Array.Sort(qualities, indices);
-      if (!Maximization.Value) Array.Reverse(indices);
-
-      var subscopes = ExecutionContext.Scope.SubScopes;
-
-      for (int i = 0; i < subscopes.Count; ++i) {
-        IOperator op;
-        if (range.Start <= i && i < range.End && Random.NextDouble() <= PruningProbability.Value)
-          op = PruningOperator;
-        else op = emptyOp;
-        var index = indices[i];
-        var subscope = subscopes[index];
-        oc.Add(ExecutionContext.CreateChildOperation(op, subscope));
-      }
-      return oc;
-    }
-
-    public override IOperation Apply() {
-      UpdateCounter.Value++;
-      if (UpdateCounter.Value != UpdateInterval.Value) return base.Apply();
-      UpdateCounter.Value = 0;
-
-      if (prunedSubtreesReducer == null || prunedTreesReducer == null || valuesCollector == null || resultsCollector == null) { InitializeOperators(); }
-
-      var prune = CreatePruningOperation();
-      var reducePrunedSubtrees = ExecutionContext.CreateChildOperation(prunedSubtreesReducer);
-      var reducePrunedTrees = ExecutionContext.CreateChildOperation(prunedTreesReducer);
-      var collectValues = ExecutionContext.CreateChildOperation(valuesCollector);
-      var collectResults = ExecutionContext.CreateChildOperation(resultsCollector);
-
-      return new OperationCollection { prune, reducePrunedSubtrees, reducePrunedTrees, collectValues, collectResults, base.Apply() };
     }
   }
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisSingleObjectiveTrainingBestSolutionAnalyzer.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisSingleObjectiveTrainingBestSolutionAnalyzer.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisSingleObjectiveTrainingBestSolutionAnalyzer.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
@@ -35,9 +35,13 @@
   [Item("SymbolicDataAnalysisSingleObjectiveTrainingBestSolutionAnalyzer", "An operator that analyzes the training best symbolic data analysis solution for single objective symbolic data analysis problems.")]
   [StorableClass]
-  public abstract class SymbolicDataAnalysisSingleObjectiveTrainingBestSolutionAnalyzer<T> : SymbolicDataAnalysisSingleObjectiveAnalyzer
+  public abstract class SymbolicDataAnalysisSingleObjectiveTrainingBestSolutionAnalyzer<T> : SymbolicDataAnalysisSingleObjectiveAnalyzer, IIterationBasedOperator
+
     where T : class, ISymbolicDataAnalysisSolution {
     private const string TrainingBestSolutionParameterName = "Best training solution";
     private const string TrainingBestSolutionQualityParameterName = "Best training solution quality";
+    private const string TrainingBestSolutionGenerationParameterName = "Best training solution generation";
     private const string UpdateAlwaysParameterName = "Always update best solution";
+    private const string IterationsParameterName = "Iterations";
+    private const string MaximumIterationsParameterName = "Maximum Iterations";
 
     #region parameter properties
@@ -48,6 +52,15 @@
       get { return (ILookupParameter<DoubleValue>)Parameters[TrainingBestSolutionQualityParameterName]; }
     }
+    public ILookupParameter<IntValue> TrainingBestSolutionGenerationParameter {
+      get { return (ILookupParameter<IntValue>)Parameters[TrainingBestSolutionGenerationParameterName]; }
+    }
     public IFixedValueParameter<BoolValue> UpdateAlwaysParameter {
       get { return (IFixedValueParameter<BoolValue>)Parameters[UpdateAlwaysParameterName]; }
+    }
+    public ILookupParameter<IntValue> IterationsParameter {
+      get { return (ILookupParameter<IntValue>)Parameters[IterationsParameterName]; }
+    }
+    public IValueLookupParameter<IntValue> MaximumIterationsParameter {
+      get { return (IValueLookupParameter<IntValue>)Parameters[MaximumIterationsParameterName]; }
     }
     #endregion
@@ -73,5 +86,8 @@
       Parameters.Add(new LookupParameter<T>(TrainingBestSolutionParameterName, "The training best symbolic data analyis solution."));
       Parameters.Add(new LookupParameter<DoubleValue>(TrainingBestSolutionQualityParameterName, "The quality of the training best symbolic data analysis solution."));
+      Parameters.Add(new LookupParameter<IntValue>(TrainingBestSolutionGenerationParameterName, "The generation in which the best training solution was found."));
       Parameters.Add(new FixedValueParameter<BoolValue>(UpdateAlwaysParameterName, "Determines if the best training solution should always be updated regardless of its quality.", new BoolValue(false)));
+      Parameters.Add(new LookupParameter<IntValue>(IterationsParameterName, "The number of performed iterations."));
+      Parameters.Add(new ValueLookupParameter<IntValue>(MaximumIterationsParameterName, "The maximum number of performed iterations.") { Hidden = true });
       UpdateAlwaysParameter.Hidden = true;
     }
@@ -83,4 +99,10 @@
         UpdateAlwaysParameter.Hidden = true;
       }
+      if (!Parameters.ContainsKey(TrainingBestSolutionGenerationParameterName))
+        Parameters.Add(new LookupParameter<IntValue>(TrainingBestSolutionGenerationParameterName, "The generation in which the best training solution was found."));
+      if (!Parameters.ContainsKey(IterationsParameterName))
+        Parameters.Add(new LookupParameter<IntValue>(IterationsParameterName, "The number of performed iterations."));
+      if (!Parameters.ContainsKey(MaximumIterationsParameterName))
+        Parameters.Add(new ValueLookupParameter<IntValue>(MaximumIterationsParameterName, "The maximum number of performed iterations.") { Hidden = true });
     }
 
@@ -104,11 +126,18 @@
         TrainingBestSolution = CreateSolution(bestTree, bestQuality);
         TrainingBestSolutionQuality = new DoubleValue(bestQuality);
+        if (IterationsParameter.ActualValue != null)
+          TrainingBestSolutionGenerationParameter.ActualValue = new IntValue(IterationsParameter.ActualValue.Value);
 
         if (!results.ContainsKey(TrainingBestSolutionParameter.Name)) {
           results.Add(new Result(TrainingBestSolutionParameter.Name, TrainingBestSolutionParameter.Description, TrainingBestSolution));
           results.Add(new Result(TrainingBestSolutionQualityParameter.Name, TrainingBestSolutionQualityParameter.Description, TrainingBestSolutionQuality));
+          if (TrainingBestSolutionGenerationParameter.ActualValue != null)
+            results.Add(new Result(TrainingBestSolutionGenerationParameter.Name, TrainingBestSolutionGenerationParameter.Description, TrainingBestSolutionGenerationParameter.ActualValue));
         } else {
           results[TrainingBestSolutionParameter.Name].Value = TrainingBestSolution;
           results[TrainingBestSolutionQualityParameter.Name].Value = TrainingBestSolutionQuality;
+          if (TrainingBestSolutionGenerationParameter.ActualValue != null)
+            results[TrainingBestSolutionGenerationParameter.Name].Value = TrainingBestSolutionGenerationParameter.ActualValue;
+
         }
       }
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisSingleObjectiveTrainingParetoBestSolutionAnalyzer.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisSingleObjectiveTrainingParetoBestSolutionAnalyzer.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisSingleObjectiveTrainingParetoBestSolutionAnalyzer.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisSingleObjectiveValidationAnalyzer.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisSingleObjectiveValidationAnalyzer.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisSingleObjectiveValidationAnalyzer.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisSingleObjectiveValidationBestSolutionAnalyzer.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisSingleObjectiveValidationBestSolutionAnalyzer.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisSingleObjectiveValidationBestSolutionAnalyzer.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
@@ -37,5 +37,5 @@
   [Item("SymbolicDataAnalysisSingleObjectiveValidationBestSolutionAnalyzer", "An operator that analyzes the validation best symbolic data analysis solution for single objective symbolic data analysis problems.")]
   [StorableClass]
-  public abstract class SymbolicDataAnalysisSingleObjectiveValidationBestSolutionAnalyzer<S, T, U> : SymbolicDataAnalysisSingleObjectiveValidationAnalyzer<T, U>
+  public abstract class SymbolicDataAnalysisSingleObjectiveValidationBestSolutionAnalyzer<S, T, U> : SymbolicDataAnalysisSingleObjectiveValidationAnalyzer<T, U>, IIterationBasedOperator
     where S : class, ISymbolicDataAnalysisSolution
     where T : class, ISymbolicDataAnalysisSingleObjectiveEvaluator<U>
@@ -43,5 +43,8 @@
     private const string ValidationBestSolutionParameterName = "Best validation solution";
     private const string ValidationBestSolutionQualityParameterName = "Best validation solution quality";
+    private const string ValidationBestSolutionGenerationParameterName = "Best validation solution generation";
     private const string UpdateAlwaysParameterName = "Always update best solution";
+    private const string IterationsParameterName = "Iterations";
+    private const string MaximumIterationsParameterName = "Maximum Iterations";
 
     #region parameter properties
@@ -52,6 +55,15 @@
       get { return (ILookupParameter<DoubleValue>)Parameters[ValidationBestSolutionQualityParameterName]; }
     }
+    public ILookupParameter<IntValue> ValidationBestSolutionGenerationParameter {
+      get { return (ILookupParameter<IntValue>)Parameters[ValidationBestSolutionGenerationParameterName]; }
+    }
     public IFixedValueParameter<BoolValue> UpdateAlwaysParameter {
       get { return (IFixedValueParameter<BoolValue>)Parameters[UpdateAlwaysParameterName]; }
+    }
+    public ILookupParameter<IntValue> IterationsParameter {
+      get { return (ILookupParameter<IntValue>)Parameters[IterationsParameterName]; }
+    }
+    public IValueLookupParameter<IntValue> MaximumIterationsParameter {
+      get { return (IValueLookupParameter<IntValue>)Parameters[MaximumIterationsParameterName]; }
     }
     #endregion
@@ -77,5 +89,8 @@
       Parameters.Add(new LookupParameter<S>(ValidationBestSolutionParameterName, "The validation best symbolic data analyis solution."));
       Parameters.Add(new LookupParameter<DoubleValue>(ValidationBestSolutionQualityParameterName, "The quality of the validation best symbolic data analysis solution."));
+      Parameters.Add(new LookupParameter<IntValue>(ValidationBestSolutionGenerationParameterName, "The generation in which the best validation solution was found."));
       Parameters.Add(new FixedValueParameter<BoolValue>(UpdateAlwaysParameterName, "Determines if the best validation solution should always be updated regardless of its quality.", new BoolValue(false)));
+      Parameters.Add(new LookupParameter<IntValue>(IterationsParameterName, "The number of performed iterations."));
+      Parameters.Add(new ValueLookupParameter<IntValue>(MaximumIterationsParameterName, "The maximum number of performed iterations.") { Hidden = true });
       UpdateAlwaysParameter.Hidden = true;
     }
@@ -84,7 +99,13 @@
     private void AfterDeserialization() {
       if (!Parameters.ContainsKey(UpdateAlwaysParameterName)) {
-        Parameters.Add(new FixedValueParameter<BoolValue>(UpdateAlwaysParameterName, "Determines if the best training solution should always be updated regardless of its quality.", new BoolValue(false)));
+        Parameters.Add(new FixedValueParameter<BoolValue>(UpdateAlwaysParameterName, "Determines if the best validation solution should always be updated regardless of its quality.", new BoolValue(false)));
         UpdateAlwaysParameter.Hidden = true;
       }
+      if (!Parameters.ContainsKey(ValidationBestSolutionGenerationParameterName))
+        Parameters.Add(new LookupParameter<IntValue>(ValidationBestSolutionGenerationParameterName, "The generation in which the best validation solution was found."));
+      if (!Parameters.ContainsKey(IterationsParameterName))
+        Parameters.Add(new LookupParameter<IntValue>(IterationsParameterName, "The number of performed iterations."));
+      if (!Parameters.ContainsKey(MaximumIterationsParameterName))
+        Parameters.Add(new ValueLookupParameter<IntValue>(MaximumIterationsParameterName, "The maximum number of performed iterations.") { Hidden = true });
     }
 
@@ -121,5 +142,4 @@
       var quality = tree
         .Take(topN)
-        .AsParallel()
         .Select(t => evaluator.Evaluate(childContext, t, problemData, rows))
         .ToArray();
@@ -138,11 +158,17 @@
         ValidationBestSolution = CreateSolution(bestTree, bestValidationQuality);
         ValidationBestSolutionQuality = new DoubleValue(bestValidationQuality);
+        if (IterationsParameter.ActualValue != null)
+          ValidationBestSolutionGenerationParameter.ActualValue = new IntValue(IterationsParameter.ActualValue.Value);
 
         if (!results.ContainsKey(ValidationBestSolutionParameter.Name)) {
           results.Add(new Result(ValidationBestSolutionParameter.Name, ValidationBestSolutionParameter.Description, ValidationBestSolution));
           results.Add(new Result(ValidationBestSolutionQualityParameter.Name, ValidationBestSolutionQualityParameter.Description, ValidationBestSolutionQuality));
+          if (ValidationBestSolutionGenerationParameter.ActualValue != null)
+            results.Add(new Result(ValidationBestSolutionGenerationParameter.Name, ValidationBestSolutionGenerationParameter.Description, ValidationBestSolutionGenerationParameter.ActualValue));
         } else {
           results[ValidationBestSolutionParameter.Name].Value = ValidationBestSolution;
           results[ValidationBestSolutionQualityParameter.Name].Value = ValidationBestSolutionQuality;
+          if (ValidationBestSolutionGenerationParameter.ActualValue != null)
+            results[ValidationBestSolutionGenerationParameter.Name].Value = ValidationBestSolutionGenerationParameter.ActualValue;
         }
       }
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisSingleObjectiveValidationParetoBestSolutionAnalyzer.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisSingleObjectiveValidationParetoBestSolutionAnalyzer.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisSingleObjectiveValidationParetoBestSolutionAnalyzer.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
@@ -120,5 +120,4 @@
         .Select(i => tree[i])
         .Take(topN)
-        .AsParallel()
         .Select(t => evaluator.Evaluate(childContext, t, problemData, rows))
         .ToArray();
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisVariableFrequencyAnalyzer.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisVariableFrequencyAnalyzer.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Analyzers/SymbolicDataAnalysisVariableFrequencyAnalyzer.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
@@ -131,5 +131,4 @@
 
       var variableFrequencies = trees
-        .AsParallel()
         .SelectMany(t => GetVariableReferences(t, aggregateLaggedVariables))
         .GroupBy(pair => pair.Key, pair => pair.Value)
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Creators/MultiSymbolicDataAnalysisExpressionCreator.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Creators/MultiSymbolicDataAnalysisExpressionCreator.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Creators/MultiSymbolicDataAnalysisExpressionCreator.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Creators/SymbolicDataAnalysisExpressionFullTreeCreator.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Creators/SymbolicDataAnalysisExpressionFullTreeCreator.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Creators/SymbolicDataAnalysisExpressionFullTreeCreator.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Creators/SymbolicDataAnalysisExpressionGrowTreeCreator.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Creators/SymbolicDataAnalysisExpressionGrowTreeCreator.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Creators/SymbolicDataAnalysisExpressionGrowTreeCreator.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Creators/SymbolicDataAnalysisExpressionRampedHalfAndHalfTreeCreator.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Creators/SymbolicDataAnalysisExpressionRampedHalfAndHalfTreeCreator.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Creators/SymbolicDataAnalysisExpressionRampedHalfAndHalfTreeCreator.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Creators/SymbolicDataAnalysisExpressionTreeCreator.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Creators/SymbolicDataAnalysisExpressionTreeCreator.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Creators/SymbolicDataAnalysisExpressionTreeCreator.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/MultiSymbolicDataAnalysisExpressionCrossover.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/MultiSymbolicDataAnalysisExpressionCrossover.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/MultiSymbolicDataAnalysisExpressionCrossover.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/SymbolicDataAnalysisExpressionContextAwareCrossover.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/SymbolicDataAnalysisExpressionContextAwareCrossover.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/SymbolicDataAnalysisExpressionContextAwareCrossover.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/SymbolicDataAnalysisExpressionCrossover.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/SymbolicDataAnalysisExpressionCrossover.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/SymbolicDataAnalysisExpressionCrossover.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/SymbolicDataAnalysisExpressionDepthConstrainedCrossover.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/SymbolicDataAnalysisExpressionDepthConstrainedCrossover.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/SymbolicDataAnalysisExpressionDepthConstrainedCrossover.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/SymbolicDataAnalysisExpressionDeterministicBestCrossover.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/SymbolicDataAnalysisExpressionDeterministicBestCrossover.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/SymbolicDataAnalysisExpressionDeterministicBestCrossover.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/SymbolicDataAnalysisExpressionProbabilisticFunctionalCrossover.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/SymbolicDataAnalysisExpressionProbabilisticFunctionalCrossover.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/SymbolicDataAnalysisExpressionProbabilisticFunctionalCrossover.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/SymbolicDataAnalysisExpressionSemanticSimilarityCrossover.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/SymbolicDataAnalysisExpressionSemanticSimilarityCrossover.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/SymbolicDataAnalysisExpressionSemanticSimilarityCrossover.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/SymbolicDataAnalysisExpressionSizefairCrossover.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/SymbolicDataAnalysisExpressionSizefairCrossover.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Crossovers/SymbolicDataAnalysisExpressionSizefairCrossover.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Evaluators/SymbolicDataAnalysisEvaluator.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Evaluators/SymbolicDataAnalysisEvaluator.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Evaluators/SymbolicDataAnalysisEvaluator.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Evaluators/SymbolicDataAnalysisMultiObjectiveEvaluator.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Evaluators/SymbolicDataAnalysisMultiObjectiveEvaluator.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Evaluators/SymbolicDataAnalysisMultiObjectiveEvaluator.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Evaluators/SymbolicDataAnalysisSingleObjectiveEvaluator.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Evaluators/SymbolicDataAnalysisSingleObjectiveEvaluator.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Evaluators/SymbolicDataAnalysisSingleObjectiveEvaluator.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Formatters/SymbolicDataAnalysisExpressionExcelFormatter.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Formatters/SymbolicDataAnalysisExpressionExcelFormatter.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Formatters/SymbolicDataAnalysisExpressionExcelFormatter.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Formatters/SymbolicDataAnalysisExpressionLatexFormatter.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Formatters/SymbolicDataAnalysisExpressionLatexFormatter.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Formatters/SymbolicDataAnalysisExpressionLatexFormatter.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Formatters/SymbolicDataAnalysisExpressionMATLABFormatter.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Formatters/SymbolicDataAnalysisExpressionMATLABFormatter.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Formatters/SymbolicDataAnalysisExpressionMATLABFormatter.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Formatters/SymbolicDataAnalysisExpressionSmalltalkFormatter.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Formatters/SymbolicDataAnalysisExpressionSmalltalkFormatter.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Formatters/SymbolicDataAnalysisExpressionSmalltalkFormatter.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Grammars/ArithmeticExpressionGrammar.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Grammars/ArithmeticExpressionGrammar.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Grammars/ArithmeticExpressionGrammar.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Grammars/FullFunctionalExpressionGrammar.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Grammars/FullFunctionalExpressionGrammar.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Grammars/FullFunctionalExpressionGrammar.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
@@ -99,4 +99,5 @@
       var or = new Or();
       var not = new Not();
+      var xor = new Xor();
 
       var timeLag = new TimeLag();
@@ -122,5 +123,5 @@
       var allSymbols = new List<Symbol>() { add, sub, mul, div, mean, sin, cos, tan, log, square, pow, sqrt, root, exp,
         airyA, airyB, bessel, cosineIntegral, dawson, erf, expIntegralEi, fresnelCosineIntegral, fresnelSineIntegral, gamma, hypCosineIntegral, hypSineIntegral, norm, psi, sineIntegral,
-        @if, gt, lt, and, or, not, timeLag, integral, derivative, constant, variableSymbol, laggedVariable,autoregressiveVariable, variableCondition };
+        @if, gt, lt, and, or, not,xor, timeLag, integral, derivative, constant, variableSymbol, laggedVariable,autoregressiveVariable, variableCondition };
       var unaryFunctionSymbols = new List<Symbol>() { square, sqrt, sin, cos, tan, log, exp, not, timeLag, integral, derivative,
         airyA, airyB, bessel, cosineIntegral, dawson, erf, expIntegralEi, fresnelCosineIntegral, fresnelSineIntegral, gamma, hypCosineIntegral, hypSineIntegral, norm, psi, sineIntegral
@@ -128,5 +129,5 @@
 
       var binaryFunctionSymbols = new List<Symbol>() { pow, root, gt, lt, variableCondition };
-      var ternarySymbols = new List<Symbol>() { add, sub, mul, div, mean, and, or };
+      var ternarySymbols = new List<Symbol>() { add, sub, mul, div, mean, and, or, xor };
       var terminalSymbols = new List<Symbol>() { variableSymbol, constant, laggedVariable, autoregressiveVariable };
 
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Grammars/TypeCoherentExpressionGrammar.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Grammars/TypeCoherentExpressionGrammar.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Grammars/TypeCoherentExpressionGrammar.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
@@ -93,4 +93,5 @@
       var or = new Or();
       var not = new Not();
+      var xor = new Xor();
       var variableCondition = new VariableCondition();
 
@@ -120,5 +121,5 @@
       var conditionSymbols = new GroupSymbol(ConditionsName, new List<ISymbol> { @if, variableCondition });
       var comparisonSymbols = new GroupSymbol(ComparisonsName, new List<ISymbol> { gt, lt });
-      var booleanOperationSymbols = new GroupSymbol(BooleanOperatorsName, new List<ISymbol> { and, or, not });
+      var booleanOperationSymbols = new GroupSymbol(BooleanOperatorsName, new List<ISymbol> { and, or, not, xor });
       var conditionalSymbols = new GroupSymbol(ConditionalSymbolsName, new List<ISymbol> { conditionSymbols, comparisonSymbols, booleanOperationSymbols });
 
@@ -148,4 +149,5 @@
       SetSubtreeCount(or, 2, 2);
       SetSubtreeCount(not, 1, 1);
+      SetSubtreeCount(xor, 2, 2);
 
       SetSubtreeCount(timeLag, 1, 1);
@@ -237,4 +239,5 @@
       Symbols.First(s => s is Average).Enabled = false;
       Symbols.First(s => s is VariableCondition).Enabled = false;
+      Symbols.First(s => s is Xor).Enabled = false;
       Symbols.First(s => s.Name == TrigonometricFunctionsName).Enabled = false;
       Symbols.First(s => s.Name == ExponentialFunctionsName).Enabled = false;
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/HeuristicLab.Problems.DataAnalysis.Symbolic-3.4.csproj
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/HeuristicLab.Problems.DataAnalysis.Symbolic-3.4.csproj	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/HeuristicLab.Problems.DataAnalysis.Symbolic-3.4.csproj	(revision 11208)
@@ -189,6 +189,6 @@
       <SubType>Code</SubType>
     </Compile>
-    <Compile Include="Interfaces\IDistanceCalculator.cs" />
-    <Compile Include="Matching\SymbolicExpressionTreeCanonicalSorter.cs" />
+    <Compile Include="Interfaces\IModelBacktransformator.cs" />
+    <Compile Include="Interfaces\IDistanceCalculator.cs" />    <Compile Include="Matching\SymbolicExpressionTreeCanonicalSorter.cs" />
     <Compile Include="Matching\SymbolicExpressionTreeEqualityComparer.cs" />
     <Compile Include="Matching\SymbolicExpressionTreeMatching.cs" />
@@ -196,5 +196,6 @@
     <Compile Include="Matching\SymbolicExpressionTreeNodeComparer.cs" />
     <Compile Include="Matching\SymbolicExpressionTreeNodeSimilarityComparer.cs" />
-    <Compile Include="SlidingWindow\GenerationalSlidingWindowAnalyzer.cs" />
+
+    <Compile Include="SymbolicExpressionTreeBacktransformator.cs" />    <Compile Include="SlidingWindow\GenerationalSlidingWindowAnalyzer.cs" />
     <Compile Include="SlidingWindow\OffspringSelectionSlidingWindowAnalyzer.cs" />
     <Compile Include="SlidingWindow\SlidingWindowAnalyzer.cs" />
@@ -203,6 +204,5 @@
     <Compile Include="SlidingWindow\SlidingWindowVisualizer.cs" />
     <Compile Include="SymbolGraph\FPGraph.cs" />
-    <Compile Include="SymbolGraph\SymbolGraph.cs" />
-    <Compile Include="SymbolicDataAnalysisExpressionPruningOperator.cs" />
+    <Compile Include="SymbolGraph\SymbolGraph.cs" />    <Compile Include="SymbolicDataAnalysisExpressionPruningOperator.cs" />
     <Compile Include="SymbolicDataAnalysisExpressionTreeSimilarityCalculator.cs" />
     <Compile Include="SymbolicDataAnalysisSolutionPruningOptimizer.cs" />
@@ -260,4 +260,5 @@
     <Compile Include="Symbols\AiryB.cs" />
     <Compile Include="Symbols\Bessel.cs" />
+    <Compile Include="Symbols\Xor.cs" />
     <Compile Include="Symbols\Erf.cs" />
     <Compile Include="Symbols\Norm.cs" />
@@ -301,5 +302,6 @@
     <Compile Include="Symbols\VariableConditionTreeNode.cs" />
     <Compile Include="Symbols\VariableTreeNode.cs" />
-    <Compile Include="Tracking\FragmentGraph\FragmentGraph.cs" />
+
+    <Compile Include="TransformationToSymbolicTreeMapper.cs" />    <Compile Include="Tracking\FragmentGraph\FragmentGraph.cs" />
     <Compile Include="Tracking\SymbolicDataAnalysisExpressionAfterCrossoverOperator.cs" />
     <Compile Include="Tracking\SymbolicDataAnalysisExpressionBeforeCrossoverOperator.cs" />
@@ -308,6 +310,5 @@
     <Compile Include="Tracking\SymbolicDataAnalysisExpressionTracing.cs" />
     <Compile Include="TreeDistance\BottomUpDistanceCalculator.cs" />
-    <Compile Include="TreeDistance\IsomorphicTreeDistance.cs" />
-    <None Include="HeuristicLab.snk" />
+    <Compile Include="TreeDistance\IsomorphicTreeDistance.cs" />    <None Include="HeuristicLab.snk" />
     <None Include="Plugin.cs.frame" />
     <None Include="Properties\AssemblyInfo.cs.frame" />
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/IModelBacktransformator.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/IModelBacktransformator.cs	(revision 11208)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/IModelBacktransformator.cs	(revision 11208)
@@ -0,0 +1,29 @@
+﻿#region License Information
+/* HeuristicLab
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ *
+ * This file is part of HeuristicLab.
+ *
+ * HeuristicLab is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * HeuristicLab is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
+ */
+#endregion
+
+using System.Collections.Generic;
+
+
+namespace HeuristicLab.Problems.DataAnalysis.Symbolic {
+  public interface IModelBacktransformator {
+    ISymbolicDataAnalysisModel Backtransform(ISymbolicDataAnalysisModel model, IEnumerable<ITransformation> transformations, string targetVariable);
+  }
+}
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisAnalyzer.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisAnalyzer.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisAnalyzer.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisBoundedOperator.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisBoundedOperator.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisBoundedOperator.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisEvaluator.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisEvaluator.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisEvaluator.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisExpressionCrossover.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisExpressionCrossover.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisExpressionCrossover.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisExpressionTreeInterpreter.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisExpressionTreeInterpreter.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisExpressionTreeInterpreter.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisGrammar.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisGrammar.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisGrammar.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisInterpreterOperator.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisInterpreterOperator.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisInterpreterOperator.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisModel.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisModel.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisModel.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisMultiObjectiveAnalyzer.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisMultiObjectiveAnalyzer.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisMultiObjectiveAnalyzer.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisMultiObjectiveEvaluator.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisMultiObjectiveEvaluator.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisMultiObjectiveEvaluator.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisProblem.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisProblem.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisProblem.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisSingleObjectiveAnalyzer.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisSingleObjectiveAnalyzer.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisSingleObjectiveAnalyzer.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisSingleObjectiveEvaluator.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisSingleObjectiveEvaluator.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisSingleObjectiveEvaluator.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisSolution.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisSolution.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisSolution.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisSolutionCreator.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisSolutionCreator.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisSolutionCreator.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisValidationAnalyzer.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisValidationAnalyzer.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interfaces/ISymbolicDataAnalysisValidationAnalyzer.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interpreter/InterpreterState.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interpreter/InterpreterState.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interpreter/InterpreterState.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interpreter/OpCodes.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interpreter/OpCodes.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interpreter/OpCodes.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
@@ -46,4 +46,5 @@
     public const byte OR = 14;
     public const byte NOT = 15;
+    public const byte XOR = 45;
 
 
@@ -99,4 +100,5 @@
       { typeof(Or), OpCodes.OR },
       { typeof(Not), OpCodes.NOT},
+      { typeof(Xor),OpCodes.XOR},
       { typeof(Average), OpCodes.Average},
       { typeof(InvokeFunction), OpCodes.Call },
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interpreter/SymbolicDataAnalysisExpressionTreeILEmittingInterpreter.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interpreter/SymbolicDataAnalysisExpressionTreeILEmittingInterpreter.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interpreter/SymbolicDataAnalysisExpressionTreeILEmittingInterpreter.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
@@ -447,4 +447,21 @@
             il.Emit(System.Reflection.Emit.OpCodes.Sub);
             il.Emit(System.Reflection.Emit.OpCodes.Neg); // * -1
+            return;
+          }
+        case OpCodes.XOR: {
+            CompileInstructions(il, state, ds);
+            il.Emit(System.Reflection.Emit.OpCodes.Ldc_I4_0);
+            il.Emit(System.Reflection.Emit.OpCodes.Cgt);// > 0
+
+            for (int i = 1; i < nArgs; i++) {
+              CompileInstructions(il, state, ds);
+              il.Emit(System.Reflection.Emit.OpCodes.Ldc_I4_0);
+              il.Emit(System.Reflection.Emit.OpCodes.Cgt);// > 0
+              il.Emit(System.Reflection.Emit.OpCodes.Xor);
+            }
+            il.Emit(System.Reflection.Emit.OpCodes.Ldc_R8, 2.0); // * 2
+            il.Emit(System.Reflection.Emit.OpCodes.Mul);
+            il.Emit(System.Reflection.Emit.OpCodes.Ldc_R8, 1.0); // - 1
+            il.Emit(System.Reflection.Emit.OpCodes.Sub);
             return;
           }
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interpreter/SymbolicDataAnalysisExpressionTreeInterpreter.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interpreter/SymbolicDataAnalysisExpressionTreeInterpreter.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interpreter/SymbolicDataAnalysisExpressionTreeInterpreter.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
@@ -344,4 +344,13 @@
             return Evaluate(dataset, ref row, state) > 0.0 ? -1.0 : 1.0;
           }
+        case OpCodes.XOR: {
+            //mkommend: XOR on multiple inputs is defined as true if the number of positive signals is odd
+            // this is equal to a consecutive execution of binary XOR operations.
+            int positiveSignals = 0;
+            for (int i = 0; i < currentInstr.nArguments; i++) {
+              if (Evaluate(dataset, ref row, state) > 0.0) positiveSignals++;
+            }
+            return positiveSignals % 2 != 0 ? 1.0 : -1.0;
+          }
         case OpCodes.GT: {
             double x = Evaluate(dataset, ref row, state);
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interpreter/SymbolicDataAnalysisExpressionTreeLinearInterpreter.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interpreter/SymbolicDataAnalysisExpressionTreeLinearInterpreter.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Interpreter/SymbolicDataAnalysisExpressionTreeLinearInterpreter.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
@@ -311,4 +311,10 @@
         } else if (instr.opCode == OpCodes.NOT) {
           instr.value = code[instr.childIndex].value > 0.0 ? -1.0 : 1.0;
+        } else if (instr.opCode == OpCodes.XOR) {
+          int positiveSignals = 0;
+          for (int j = 0; j < instr.nArguments; j++) {
+            if (code[instr.childIndex + j].value > 0.0) positiveSignals++;
+          }
+          instr.value = positiveSignals % 2 != 0 ? 1.0 : -1.0;
         } else if (instr.opCode == OpCodes.GT) {
           double x = code[instr.childIndex].value;
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Matching/SymbolicExpressionTreeNodeSimilarityComparer.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Matching/SymbolicExpressionTreeNodeSimilarityComparer.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Matching/SymbolicExpressionTreeNodeSimilarityComparer.cs	(revision 11208)
@@ -30,6 +30,6 @@
   public class SymbolicExpressionTreeNodeSimilarityComparer : Item, ISymbolicExpressionTreeNodeSimilarityComparer {
     [StorableConstructor]
-    private SymbolicExpressionTreeNodeSimilarityComparer(bool deserializing) : base(deserializing) { }
-    private SymbolicExpressionTreeNodeSimilarityComparer(SymbolicExpressionTreeNodeSimilarityComparer original, Cloner cloner)
+    protected SymbolicExpressionTreeNodeSimilarityComparer(bool deserializing) : base(deserializing) { }
+    protected SymbolicExpressionTreeNodeSimilarityComparer(SymbolicExpressionTreeNodeSimilarityComparer original, Cloner cloner)
       : base(original, cloner) {
       matchConstantValues = original.matchConstantValues;
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Plugin.cs.frame
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Plugin.cs.frame	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Plugin.cs.frame	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
@@ -26,5 +26,5 @@
 
 namespace HeuristicLab.Problems.DataAnalysis.Symbolic {
-  [Plugin("HeuristicLab.Problems.DataAnalysis.Symbolic","Provides base classes for symbolic data analysis tasks.", "3.4.5.$WCREV$")]
+  [Plugin("HeuristicLab.Problems.DataAnalysis.Symbolic","Provides base classes for symbolic data analysis tasks.", "3.4.6.$WCREV$")]
   [PluginFile("HeuristicLab.Problems.DataAnalysis.Symbolic-3.4.dll", PluginFileType.Assembly)]
   [PluginDependency("HeuristicLab.ALGLIB", "3.7.0")]
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Properties/AssemblyInfo.cs.frame
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Properties/AssemblyInfo.cs.frame	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Properties/AssemblyInfo.cs.frame	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
@@ -31,5 +31,5 @@
 [assembly: AssemblyCompany("")]
 [assembly: AssemblyProduct("HeuristicLab")]
-[assembly: AssemblyCopyright("(c) 2002-2013 HEAL")]
+[assembly: AssemblyCopyright("(c) 2002-2014 HEAL")]
 [assembly: AssemblyTrademark("")]
 [assembly: AssemblyCulture("")]
@@ -53,3 +53,3 @@
 // by using the '*' as shown below:
 [assembly: AssemblyVersion("3.4.0.0")]
-[assembly: AssemblyFileVersion("3.4.5.$WCREV$")]
+[assembly: AssemblyFileVersion("3.4.6.$WCREV$")]
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/SymbolicDataAnalysisExpressionPruningOperator.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/SymbolicDataAnalysisExpressionPruningOperator.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/SymbolicDataAnalysisExpressionPruningOperator.cs	(revision 11208)
@@ -85,10 +85,17 @@
     }
     #endregion
+
     #region properties
     protected IDataAnalysisProblemData ProblemData { get { return ProblemDataParameter.ActualValue; } }
     protected ISymbolicDataAnalysisSolutionImpactValuesCalculator ImpactValuesCalculator { get { return ImpactValuesCalculatorParameter.Value; } }
     protected IntRange FitnessCalculationPartition { get { return FitnessCalculationPartitionParameter.ActualValue; } }
-    protected BoolValue PruneOnlyZeroImpactNodes { get { return PruneOnlyZeroImpactNodesParameter.Value; } }
-    protected DoubleValue NodeImpactThreshold { get { return NodeImpactThresholdParameter.Value; } }
+    protected bool PruneOnlyZeroImpactNodes {
+      get { return PruneOnlyZeroImpactNodesParameter.Value.Value; }
+      set { PruneOnlyZeroImpactNodesParameter.Value.Value = value; }
+    }
+    protected double NodeImpactThreshold {
+      get { return NodeImpactThresholdParameter.Value.Value; }
+      set { NodeImpactThresholdParameter.Value.Value = value; }
+    }
     protected ISymbolicExpressionTree SymbolicExpressionTree { get { return SymbolicExpressionTreeParameter.ActualValue; } }
     protected DoubleValue Quality { get { return QualityParameter.ActualValue; } }
@@ -117,9 +124,13 @@
       #endregion
     }
+
+    protected abstract ISymbolicDataAnalysisModel CreateModel();
+
+    protected abstract double Evaluate(IDataAnalysisModel model);
+
     public override IOperation Apply() {
       var model = CreateModel();
       var nodes = SymbolicExpressionTree.Root.GetSubtree(0).GetSubtree(0).IterateNodesPrefix().ToList();
-      var rows = Enumerable.Range(FitnessCalculationPartition.Start, FitnessCalculationPartition.Size).ToList();
-
+      var rows = Enumerable.Range(FitnessCalculationPartition.Start, FitnessCalculationPartition.Size);
       var prunedSubtrees = 0;
       var prunedTrees = 0;
@@ -134,8 +145,13 @@
         ImpactValuesCalculator.CalculateImpactAndReplacementValues(model, node, ProblemData, rows, out impactValue, out replacementValue, quality);
 
-        if (PruneOnlyZeroImpactNodes.Value && (!impactValue.IsAlmost(0.0))) continue;
-        else if (NodeImpactThreshold.Value < impactValue) continue;
+        if (PruneOnlyZeroImpactNodes) {
+          if (!impactValue.IsAlmost(0.0)) continue;
+        } else if (NodeImpactThreshold < impactValue) {
+          continue;
+        }
 
-        var constantNode = new ConstantTreeNode(new Constant()) { Value = replacementValue };
+        var constantNode = (ConstantTreeNode)node.Grammar.GetSymbol("Constant").CreateTreeNode();
+        constantNode.Value = replacementValue;
+
         ReplaceWithConstant(node, constantNode);
         i += node.GetLength() - 1; // skip subtrees under the node that was folded
@@ -152,4 +168,5 @@
       return base.Apply();
     }
+
     private static void ReplaceWithConstant(ISymbolicExpressionTreeNode original, ISymbolicExpressionTreeNode replacement) {
       var parent = original.Parent;
@@ -158,6 +175,4 @@
       parent.InsertSubtree(i, replacement);
     }
-    protected abstract ISymbolicDataAnalysisModel CreateModel();
-    protected abstract double Evaluate(IDataAnalysisModel model);
   }
 }
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/SymbolicDataAnalysisExpressionTreeSimplifier.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/SymbolicDataAnalysisExpressionTreeSimplifier.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/SymbolicDataAnalysisExpressionTreeSimplifier.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/SymbolicDataAnalysisModel.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/SymbolicDataAnalysisModel.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/SymbolicDataAnalysisModel.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/SymbolicDataAnalysisMultiObjectiveProblem.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/SymbolicDataAnalysisMultiObjectiveProblem.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/SymbolicDataAnalysisMultiObjectiveProblem.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/SymbolicDataAnalysisProblem.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/SymbolicDataAnalysisProblem.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/SymbolicDataAnalysisProblem.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/SymbolicDataAnalysisSingleObjectiveProblem.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/SymbolicDataAnalysisSingleObjectiveProblem.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/SymbolicDataAnalysisSingleObjectiveProblem.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/SymbolicDataAnalysisSolutionImpactValuesCalculator.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/SymbolicDataAnalysisSolutionImpactValuesCalculator.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/SymbolicDataAnalysisSolutionImpactValuesCalculator.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/SymbolicExpressionTreeBacktransformator.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/SymbolicExpressionTreeBacktransformator.cs	(revision 11208)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/SymbolicExpressionTreeBacktransformator.cs	(revision 11208)
@@ -0,0 +1,97 @@
+﻿#region License Information
+/* HeuristicLab
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ *
+ * This file is part of HeuristicLab.
+ *
+ * HeuristicLab is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * HeuristicLab is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
+ */
+#endregion
+
+using System.Collections.Generic;
+using System.Linq;
+using HeuristicLab.Common;
+using HeuristicLab.Encodings.SymbolicExpressionTreeEncoding;
+
+namespace HeuristicLab.Problems.DataAnalysis.Symbolic {
+  public class SymbolicExpressionTreeBacktransformator : IModelBacktransformator {
+    private readonly ITransformationMapper<ISymbolicExpressionTreeNode> transformationMapper;
+
+    public SymbolicExpressionTreeBacktransformator(ITransformationMapper<ISymbolicExpressionTreeNode> transformationMapper) {
+      this.transformationMapper = transformationMapper;
+    }
+
+    public ISymbolicDataAnalysisModel Backtransform(ISymbolicDataAnalysisModel model, IEnumerable<ITransformation> transformations, string targetVariable) {
+      var symbolicModel = (ISymbolicDataAnalysisModel)model.Clone();
+
+      foreach (var transformation in transformations.Reverse()) {
+        ApplyBacktransformation(transformation, symbolicModel.SymbolicExpressionTree, targetVariable);
+      }
+
+      return symbolicModel;
+    }
+
+    private void ApplyBacktransformation(ITransformation transformation, ISymbolicExpressionTree symbolicExpressionTree, string targetVariable) {
+      if (transformation.Column != targetVariable) {
+        var variableNodes = symbolicExpressionTree.IterateNodesBreadth()
+          .OfType<VariableTreeNode>()
+          .Where(n => n.VariableName == transformation.Column);
+        ApplyRegularBacktransformation(transformation, variableNodes);
+      } else if (!(transformation is CopyColumnTransformation)) {
+        ApplyInverseBacktransformation(transformation, symbolicExpressionTree);
+      }
+    }
+
+    private void ApplyRegularBacktransformation(ITransformation transformation, IEnumerable<VariableTreeNode> variableNodes) {
+      foreach (var variableNode in variableNodes) {
+        // generate new subtrees because same subtree cannot be added more than once
+        var transformationTree = transformationMapper.GenerateModel(transformation);
+        SwapVariableWithTree(variableNode, transformationTree);
+      }
+    }
+
+    private void ApplyInverseBacktransformation(ITransformation transformation, ISymbolicExpressionTree symbolicExpressionTree) {
+      var startSymbol = symbolicExpressionTree.Root.GetSubtree(0);
+      var modelTree = startSymbol.GetSubtree(0);
+      startSymbol.RemoveSubtree(0);
+
+      var transformationTree = transformationMapper.GenerateInverseModel(transformation);
+      var variableNode = transformationTree.IterateNodesBreadth()
+        .OfType<VariableTreeNode>()
+        .Single(n => n.VariableName == transformation.Column);
+
+      SwapVariableWithTree(variableNode, modelTree);
+
+      startSymbol.AddSubtree(transformationTree);
+    }
+
+    private void SwapVariableWithTree(VariableTreeNode variableNode, ISymbolicExpressionTreeNode treeNode) {
+      var parent = variableNode.Parent;
+      int index = parent.IndexOfSubtree(variableNode);
+      parent.RemoveSubtree(index);
+
+      if (!variableNode.Weight.IsAlmost(1.0))
+        treeNode = CreateNodeFromWeight(treeNode, variableNode);
+
+      parent.InsertSubtree(index, treeNode);
+    }
+
+    private ISymbolicExpressionTreeNode CreateNodeFromWeight(ISymbolicExpressionTreeNode transformationTree, VariableTreeNode variableNode) {
+      var multiplicationNode = new SymbolicExpressionTreeNode(new Multiplication());
+      multiplicationNode.AddSubtree(new ConstantTreeNode(new Constant()) { Value = variableNode.Weight });
+      multiplicationNode.AddSubtree(transformationTree);
+      return multiplicationNode;
+    }
+  }
+}
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Addition.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Addition.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Addition.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/AiryA.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/AiryA.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/AiryA.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/AiryB.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/AiryB.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/AiryB.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/And.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/And.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/And.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/AutoregressiveVariable.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/AutoregressiveVariable.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/AutoregressiveVariable.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Average.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Average.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Average.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Bessel.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Bessel.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Bessel.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Constant.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Constant.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Constant.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/ConstantTreeNode.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/ConstantTreeNode.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/ConstantTreeNode.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Cosine.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Cosine.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Cosine.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/CosineIntegral.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/CosineIntegral.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/CosineIntegral.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Dawson.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Dawson.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Dawson.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Derivative.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Derivative.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Derivative.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Division.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Division.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Division.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Erf.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Erf.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Erf.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Exponential.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Exponential.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Exponential.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/ExponentialIntegralEi.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/ExponentialIntegralEi.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/ExponentialIntegralEi.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/FresnelCosineIntegral.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/FresnelCosineIntegral.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/FresnelCosineIntegral.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/FresnelSineIntegral.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/FresnelSineIntegral.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/FresnelSineIntegral.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Gamma.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Gamma.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Gamma.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/GreaterThan.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/GreaterThan.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/GreaterThan.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/HyperbolicCosineIntegral.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/HyperbolicCosineIntegral.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/HyperbolicCosineIntegral.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/HyperbolicSineIntegral.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/HyperbolicSineIntegral.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/HyperbolicSineIntegral.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/ILaggedTreeNode.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/ILaggedTreeNode.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/ILaggedTreeNode.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/IfThenElse.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/IfThenElse.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/IfThenElse.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Integral.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Integral.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Integral.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/LaggedSymbol.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/LaggedSymbol.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/LaggedSymbol.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/LaggedTreeNode.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/LaggedTreeNode.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/LaggedTreeNode.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/LaggedVariable.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/LaggedVariable.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/LaggedVariable.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/LaggedVariableTreeNode.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/LaggedVariableTreeNode.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/LaggedVariableTreeNode.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/LessThan.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/LessThan.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/LessThan.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Logarithm.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Logarithm.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Logarithm.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Multiplication.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Multiplication.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Multiplication.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Norm.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Norm.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Norm.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Not.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Not.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Not.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Or.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Or.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Or.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Power.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Power.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Power.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Psi.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Psi.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Psi.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Root.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Root.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Root.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Sine.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Sine.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Sine.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/SineIntegral.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/SineIntegral.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/SineIntegral.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Square.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Square.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Square.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/SquareRoot.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/SquareRoot.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/SquareRoot.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Subtraction.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Subtraction.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Subtraction.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Tangent.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Tangent.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Tangent.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/TimeLag.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/TimeLag.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/TimeLag.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Variable.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Variable.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Variable.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/VariableCondition.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/VariableCondition.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/VariableCondition.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/VariableConditionTreeNode.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/VariableConditionTreeNode.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/VariableConditionTreeNode.cs	(revision 11208)
@@ -1,5 +1,5 @@
 ﻿#region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/VariableTreeNode.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/VariableTreeNode.cs	(revision 11197)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/VariableTreeNode.cs	(revision 11208)
@@ -1,5 +1,5 @@
 #region License Information
 /* HeuristicLab
- * Copyright (C) 2002-2013 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
  *
  * This file is part of HeuristicLab.
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Xor.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Xor.cs	(revision 11208)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/Symbols/Xor.cs	(revision 11208)
@@ -0,0 +1,48 @@
+#region License Information
+/* HeuristicLab
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ *
+ * This file is part of HeuristicLab.
+ *
+ * HeuristicLab is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * HeuristicLab is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
+ */
+#endregion
+
+using HeuristicLab.Common;
+using HeuristicLab.Core;
+using HeuristicLab.Encodings.SymbolicExpressionTreeEncoding;
+using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
+namespace HeuristicLab.Problems.DataAnalysis.Symbolic {
+  [StorableClass]
+  [Item("Xor", "Symbol that represents the boolean XOR operator.")]
+  public sealed class Xor : Symbol {
+    private const int minimumArity = 1;
+    private const int maximumArity = byte.MaxValue;
+
+    public override int MinimumArity {
+      get { return minimumArity; }
+    }
+    public override int MaximumArity {
+      get { return maximumArity; }
+    }
+
+    [StorableConstructor]
+    private Xor(bool deserializing) : base(deserializing) { }
+    private Xor(Xor original, Cloner cloner) : base(original, cloner) { }
+    public override IDeepCloneable Clone(Cloner cloner) {
+      return new Xor(this, cloner);
+    }
+    public Xor() : base("Xor", "Symbol that represents the boolean XOR operator.") { }
+  }
+}
Index: branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/TransformationToSymbolicTreeMapper.cs
===================================================================
--- branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/TransformationToSymbolicTreeMapper.cs	(revision 11208)
+++ branches/HeuristicLab.EvolutionTracking/HeuristicLab.Problems.DataAnalysis.Symbolic/3.4/TransformationToSymbolicTreeMapper.cs	(revision 11208)
@@ -0,0 +1,294 @@
+﻿#region License Information
+/* HeuristicLab
+ * Copyright (C) 2002-2014 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
+ *
+ * This file is part of HeuristicLab.
+ *
+ * HeuristicLab is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * HeuristicLab is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
+ */
+#endregion
+
+using System;
+using HeuristicLab.Encodings.SymbolicExpressionTreeEncoding;
+
+namespace HeuristicLab.Problems.DataAnalysis.Symbolic {
+  public class TransformationToSymbolicTreeMapper : ITransformationMapper<ISymbolicExpressionTreeNode> {
+    private ITransformation transformation;
+    private string column;
+
+    #region ITransformationMapper<ISymbolicExpressionTree> Members
+
+    public ISymbolicExpressionTreeNode GenerateModel(ITransformation transformation) {
+      InitComponents(transformation);
+
+      if (transformation is LinearTransformation) {
+        return GenerateModelForLinearTransformation();
+      } else if (transformation is ExponentialTransformation) {
+        return GenerateModelForExponentialTransformation();
+      } else if (transformation is LogarithmicTransformation) {
+        return GenerateModelForLogarithmicTransformation();
+      } else if (transformation is PowerTransformation) {
+        return GenerateModelForPowerTransformation();
+      } else if (transformation is ReciprocalTransformation) {
+        return GenerateModelForReciprocalTransformation();
+      } else if (transformation is ShiftStandardDistributionTransformation) {
+        return GenerateModelForShiftStandardDistributionTransformation();
+      } else if (transformation is CopyColumnTransformation) {
+        return GenerateTreeNodeForCopyColumnTransformation();
+      }
+      throw new NotImplementedException();
+    }
+
+    public ISymbolicExpressionTreeNode GenerateInverseModel(ITransformation transformation) {
+      InitComponents(transformation);
+
+      if (transformation is LinearTransformation) {
+        return GenerateInverseModelForLinearTransformation();
+      } else if (transformation is ExponentialTransformation) {
+        return GenerateInverseModelForExponentialTransformation();
+      } else if (transformation is LogarithmicTransformation) {
+        return GenerateInverseModelForLogarithmicTransformation();
+      } else if (transformation is PowerTransformation) {
+        return GenerateInverseModelForPowerTransformation();
+      } else if (transformation is ReciprocalTransformation) {
+        return GenerateInverseModelForReciprocalTransformation();
+      } else if (transformation is ShiftStandardDistributionTransformation) {
+        GenerateInverseModelForShiftStandardDistributionTransformation();
+      } else if (transformation is CopyColumnTransformation) {
+        return GenerateTreeNodeForCopyColumnTransformation();
+      }
+
+      throw new NotImplementedException();
+    }
+
+    #endregion
+
+    // helper
+
+    private ISymbolicExpressionTreeNode GenerateModelForLinearTransformation() {
+      var linearTransformation = (LinearTransformation)transformation;
+      var kValue = linearTransformation.Multiplier;
+      var dValue = linearTransformation.Addend;
+
+      // k * x
+      var multiplicationNode = new Multiplication().CreateTreeNode();
+      var kNode = CreateConstantTreeNode("k", kValue);
+      var xNode = CreateVariableTreeNode(column, "x");
+      multiplicationNode.AddSubtree(kNode);
+      multiplicationNode.AddSubtree(xNode);
+
+      // ( k * x ) + d
+      var additionNode = new Addition().CreateTreeNode();
+      var dNode = CreateConstantTreeNode("d", dValue);
+      additionNode.AddSubtree(multiplicationNode);
+      additionNode.AddSubtree(dNode);
+
+      return additionNode;
+    }
+
+    private ISymbolicExpressionTreeNode GenerateInverseModelForLinearTransformation() {
+      var linearTransformation = (LinearTransformation)transformation;
+      var kValue = linearTransformation.Multiplier;
+      var dValue = linearTransformation.Addend;
+
+      // x - d
+      var substractionNode = new Subtraction().CreateTreeNode();
+      var dNode = CreateConstantTreeNode("d", dValue);
+      var xNode = CreateVariableTreeNode(column, "x");
+      substractionNode.AddSubtree(xNode);
+      substractionNode.AddSubtree(dNode);
+
+      // ( x - d ) / k
+      var divisionNode = new Division().CreateTreeNode();
+      var kNode = CreateConstantTreeNode("k", kValue);
+      divisionNode.AddSubtree(substractionNode);
+      divisionNode.AddSubtree(kNode);
+
+      return divisionNode;
+    }
+
+
+    private ISymbolicExpressionTreeNode GenerateModelForExponentialTransformation() {
+      var exponentialTransformation = (ExponentialTransformation)transformation;
+      var bValue = exponentialTransformation.Base;
+
+      return GenTreePow_b_x(bValue);
+    }
+
+    private ISymbolicExpressionTreeNode GenerateInverseModelForExponentialTransformation() {
+      var exponentialTransformation = (ExponentialTransformation)transformation;
+      var bValue = exponentialTransformation.Base;
+
+      return GenTreeLog_x_b(bValue);
+    }
+
+
+    private ISymbolicExpressionTreeNode GenerateModelForLogarithmicTransformation() {
+      var logarithmicTransformation = (LogarithmicTransformation)transformation;
+      var bValue = logarithmicTransformation.Base;
+
+      return GenTreeLog_x_b(bValue);
+    }
+
+    private ISymbolicExpressionTreeNode GenerateInverseModelForLogarithmicTransformation() {
+      var logarithmicTransformation = (LogarithmicTransformation)transformation;
+      var bValue = logarithmicTransformation.Base;
+
+      return GenTreePow_b_x(bValue);
+    }
+
+
+    private ISymbolicExpressionTreeNode GenerateModelForPowerTransformation() {
+      var powerTransformation = (PowerTransformation)transformation;
+      var expValue = powerTransformation.Exponent;
+
+      // x ^ exp
+      var powerNode = new Power().CreateTreeNode();
+      var xNode = CreateVariableTreeNode(column, "x");
+      var expNode = CreateConstantTreeNode("exp", expValue);
+      powerNode.AddSubtree(xNode);
+      powerNode.AddSubtree(expNode);
+
+      return powerNode;
+    }
+
+    private ISymbolicExpressionTreeNode GenerateInverseModelForPowerTransformation() {
+      var powerTransformation = (PowerTransformation)transformation;
+      var expValue = powerTransformation.Exponent;
+
+      // rt(x, b)
+      var rootNode = new Root().CreateTreeNode();
+      var xNode = CreateVariableTreeNode(column, "x");
+      var bNode = CreateConstantTreeNode("b", expValue);
+      rootNode.AddSubtree(xNode);
+      rootNode.AddSubtree(bNode);
+
+      return rootNode;
+    }
+
+
+    private ISymbolicExpressionTreeNode GenerateModelForReciprocalTransformation() {
+      return GenTreeDiv_1_x();
+    }
+
+    private ISymbolicExpressionTreeNode GenerateInverseModelForReciprocalTransformation() {
+      return GenTreeDiv_1_x();
+    }
+
+
+    private ISymbolicExpressionTreeNode GenerateModelForShiftStandardDistributionTransformation() {
+      var shiftStandardDistributionTransformation = (ShiftStandardDistributionTransformation)transformation;
+      var m_orgValue = shiftStandardDistributionTransformation.OriginalMean;
+      var s_orgValue = shiftStandardDistributionTransformation.OriginalStandardDeviation;
+      var m_tarValue = shiftStandardDistributionTransformation.Mean;
+      var s_tarValue = shiftStandardDistributionTransformation.StandardDeviation;
+
+      return GenTreeShiftStdDist(column, m_orgValue, s_orgValue, m_tarValue, s_tarValue);
+    }
+
+    private ISymbolicExpressionTreeNode GenerateInverseModelForShiftStandardDistributionTransformation() {
+      var shiftStandardDistributionTransformation = (ShiftStandardDistributionTransformation)transformation;
+      var m_orgValue = shiftStandardDistributionTransformation.OriginalMean;
+      var s_orgValue = shiftStandardDistributionTransformation.OriginalStandardDeviation;
+      var m_tarValue = shiftStandardDistributionTransformation.Mean;
+      var s_tarValue = shiftStandardDistributionTransformation.StandardDeviation;
+
+      return GenTreeShiftStdDist(column, m_tarValue, s_tarValue, m_orgValue, s_orgValue);
+    }
+
+    private ISymbolicExpressionTreeNode GenerateTreeNodeForCopyColumnTransformation() {
+      var copyColumnTransformation = (CopyColumnTransformation)transformation;
+      var copiedColumnName = copyColumnTransformation.CopiedColumnName;
+
+      return CreateVariableTreeNode(copiedColumnName, copiedColumnName + "(original)");
+    }
+
+    // helper's helper:
+
+    private ISymbolicExpressionTreeNode GenTreeLog_x_b(double b) {
+      // log(x, b)
+      var logNode = new Logarithm().CreateTreeNode();
+      var bNode = CreateConstantTreeNode("b", b);
+      var xNode = CreateVariableTreeNode(column, "x");
+      logNode.AddSubtree(xNode);
+      logNode.AddSubtree(bNode);
+
+      return logNode;
+    }
+
+    private ISymbolicExpressionTreeNode GenTreePow_b_x(double b) {
+      // b ^ x
+      var powerNode = new Power().CreateTreeNode();
+      var bNode = CreateConstantTreeNode("b", b);
+      var xNode = CreateVariableTreeNode(column, "x");
+      powerNode.AddSubtree(bNode);
+      powerNode.AddSubtree(xNode);
+
+      return powerNode;
+    }
+
+    private ISymbolicExpressionTreeNode GenTreeDiv_1_x() {
+      // 1 / x
+      var divNode = new Division().CreateTreeNode();
+      var oneNode = CreateConstantTreeNode("1", 1.0);
+      var xNode = CreateVariableTreeNode(column, "x");
+      divNode.AddSubtree(oneNode);
+      divNode.AddSubtree(xNode);
+
+      return divNode;
+    }
+
+    private ISymbolicExpressionTreeNode GenTreeShiftStdDist(string variable, double m_org, double s_org, double m_tar, double s_tar) {
+      // x - m_org
+      var substractionNode = new Subtraction().CreateTreeNode();
+      var xNode = CreateVariableTreeNode(variable, "x");
+      var m_orgNode = CreateConstantTreeNode("m_org", m_org);
+      substractionNode.AddSubtree(xNode);
+      substractionNode.AddSubtree(m_orgNode);
+
+      // (x - m_org) / s_org
+      var divisionNode = new Division().CreateTreeNode();
+      var s_orgNode = CreateConstantTreeNode("s_org", s_org);
+      divisionNode.AddSubtree(substractionNode);
+      divisionNode.AddSubtree(s_orgNode);
+
+      // ((x - m_org) / s_org ) * s_tar
+      var multiplicationNode = new Multiplication().CreateTreeNode();
+      var s_tarNode = CreateConstantTreeNode("s_tar", s_tar);
+      multiplicationNode.AddSubtree(divisionNode);
+      multiplicationNode.AddSubtree(s_tarNode);
+
+      // ((x - m_org) / s_org ) * s_tar + m_tar
+      var additionNode = new Addition().CreateTreeNode();
+      var m_tarNode = CreateConstantTreeNode("m_tar", m_tar);
+      additionNode.AddSubtree(multiplicationNode);
+      additionNode.AddSubtree(m_tarNode);
+
+      return additionNode;
+    }
+
+    private ConstantTreeNode CreateConstantTreeNode(string description, double value) {
+      return new ConstantTreeNode(new Constant()) { Value = value };
+    }
+
+    private VariableTreeNode CreateVariableTreeNode(string name, string description) {
+      return new VariableTreeNode(new Variable(name, description)) { VariableName = name, Weight = 1.0 };
+    }
+
+    private void InitComponents(ITransformation transformation) {
+      this.transformation = transformation;
+      column = transformation.Column;
+    }
+  }
+}
