initTargetFunctions();
conditionFunctions = new HashSet(targetFunctions);
// add condition functions from BagFunction
conditionFunctions.addAll((new ConditionBagFunctionCluster()).
getSupportedFunctions());
// add condition functions from SetFunction
conditionFunctions.addAll((new ConditionSetFunctionCluster()).
getSupportedFunctions());
// add condition functions from HigherOrderFunction