diff --git a/src/main/java/de/dhbwstuttgart/core/JavaTXCompiler.java b/src/main/java/de/dhbwstuttgart/core/JavaTXCompiler.java
index 157c6b82..8c2b6d41 100644
--- a/src/main/java/de/dhbwstuttgart/core/JavaTXCompiler.java
+++ b/src/main/java/de/dhbwstuttgart/core/JavaTXCompiler.java
@@ -135,50 +135,67 @@ public class JavaTXCompiler {
 			//sf enthaelt neues Source-File, neue Klassen-Objekte und neue 
 			//ArrayListen-Objekte fuer Fields, Construktoren und Methoden
 			//Alle anderen Objekte werden nur kopiert.
-			sf.KlassenVektor.forEach(cl -> {
-				ClassOrInterface superclass = null;
-				if (cl.getSuperClass().getName().equals(new JavaClassName("java.lang.Object"))) {
-					superclass = objectClass;
-				}	
-				else {
-					Optional<ClassOrInterface> optSuperclass = 
-							importedClasses.stream().filter(x -> x.getClassName().equals(
+			SourceFile sf_new = sf;
+			sf.KlassenVektor.forEach(cl -> addMethods(sf_new, cl, importedClasses, objectClass));
+			allClasses.addAll(sf.getClasses());
+		}
+        allClasses.addAll(importedClasses);
+        return new TYPE(sourceFiles.values(), allClasses).getConstraints();
+    }
+			
+	void addMethods(SourceFile sf, ClassOrInterface cl, List<ClassOrInterface> importedClasses, ClassOrInterface objectClass) {	
+		if (!cl.areMethodsAdded()) {
+			ClassOrInterface superclass = null;
+			if (cl.getSuperClass().getName().equals(new JavaClassName("java.lang.Object"))) {
+				superclass = objectClass;
+			}	
+			else {
+				Optional<ClassOrInterface> optSuperclass = 
+						importedClasses.stream().filter(x -> x.getClassName().equals(
 									cl.getSuperClass().getName())).findFirst();
+				if (optSuperclass.isPresent()) {
+					superclass = optSuperclass.get();
+				}
+				else {	
+					optSuperclass = 
+							sf.KlassenVektor.stream().filter(x -> x.getClassName().equals(
+										cl.getSuperClass().getName())).findFirst();
 					if (optSuperclass.isPresent()) {
 						superclass = optSuperclass.get();
+						addMethods(sf, superclass, importedClasses, objectClass);	
 					}
-					else {	
+					else {
 						//throw new ClassNotFoundException("");
 					}
 				}
-				Iterator<RefTypeOrTPHOrWildcardOrGeneric> paraIt= cl.getSuperClass().getParaList().iterator();
-				Iterator<GenericTypeVar> tvarVarIt = superclass.getGenerics().iterator();
+			}
+			Iterator<RefTypeOrTPHOrWildcardOrGeneric> paraIt= cl.getSuperClass().getParaList().iterator();
+			Iterator<GenericTypeVar> tvarVarIt = superclass.getGenerics().iterator();
 				
-				HashMap<String, RefTypeOrTPHOrWildcardOrGeneric> gtvs = new HashMap<>();
-				while (paraIt.hasNext()) { 
-					gtvs.put(tvarVarIt.next().getName(), paraIt.next());
-				}
-				Iterator<Method> methodIt = superclass.getMethods().iterator();
-				while(methodIt.hasNext()) {
-					Method m = methodIt.next();
-					ParameterList newParaList = new ParameterList(
+			HashMap<String, RefTypeOrTPHOrWildcardOrGeneric> gtvs = new HashMap<>();
+			while (paraIt.hasNext()) { 
+				gtvs.put(tvarVarIt.next().getName(), paraIt.next());
+			}
+			Iterator<Method> methodIt = superclass.getMethods().iterator();
+			while(methodIt.hasNext()) {
+				Method m = methodIt.next();
+				ParameterList newParaList = new ParameterList(
 					m.getParameterList()
 					 .getFormalparalist()
 					 .stream()
 					 .map(fp -> new FormalParameter(fp.getName(), fp.getType().acceptTV(new TypeExchanger(gtvs)), fp.getOffset()))
 					 .collect(Collectors.toCollection(ArrayList::new)), m.getParameterList().getOffset());
-					cl.getMethods().add(new Method(m.modifier, m.name, m.getReturnType().acceptTV(new TypeExchanger(gtvs)), newParaList, m.block,
+				cl.getMethods().add(new Method(m.modifier, m.name, m.getReturnType().acceptTV(new TypeExchanger(gtvs)), newParaList, m.block,
 							  //new GenericDeclarationList(newGenericsList, ((GenericDeclarationList)m.getGenerics()).getOffset()), 
-							(GenericDeclarationList)m.getGenerics(),
-							m.getOffset()));
-				}
+						(GenericDeclarationList)m.getGenerics(),
+						m.getOffset()));
+			}
 				
-			});
-            allClasses.addAll(sf.getClasses());
 		}
-        allClasses.addAll(importedClasses);
-        return new TYPE(sourceFiles.values(), allClasses).getConstraints();
-    }
+		cl.setMethodsAdded();
+	}
+            
+   
 
     public List<ClassOrInterface> getAvailableClasses(SourceFile forSourceFile) throws ClassNotFoundException {
         //PL 2018-09-18: List durch Set ersetzt, damit die Klassen nur einmal hinzugefuegt werden 
diff --git a/src/main/java/de/dhbwstuttgart/syntaxtree/ClassOrInterface.java b/src/main/java/de/dhbwstuttgart/syntaxtree/ClassOrInterface.java
index 87f11980..d75602d6 100644
--- a/src/main/java/de/dhbwstuttgart/syntaxtree/ClassOrInterface.java
+++ b/src/main/java/de/dhbwstuttgart/syntaxtree/ClassOrInterface.java
@@ -23,6 +23,7 @@ import java.util.Optional;
  * Stellt jede Art von Klasse dar. Auch abstrakte Klassen und Interfaces
  */
 public class ClassOrInterface extends SyntaxTreeNode implements TypeScope{
+  private Boolean methodAdded = false; //wird benoetigt bei in JavaTXCompiler.getConstraints()
   protected int modifiers;
   protected JavaClassName name;
   private List<Field> fields = new ArrayList<>();
@@ -68,6 +69,16 @@ public class ClassOrInterface extends SyntaxTreeNode implements TypeScope{
 	  this.constructors = new ArrayList<>(cl.constructors);
   }
   
+  //Gets if it is added
+  public Boolean areMethodsAdded() {
+	  return methodAdded;
+  }
+  
+  //Sets taht it is added
+  public void setMethodsAdded() {
+	methodAdded = true;	
+  }
+  
   // Gets class name
   public JavaClassName getClassName(){
     return this.name;
diff --git a/src/main/java/de/dhbwstuttgart/typeinference/unify/TypeUnifyTask.java b/src/main/java/de/dhbwstuttgart/typeinference/unify/TypeUnifyTask.java
index 53390bbc..8f13f01f 100644
--- a/src/main/java/de/dhbwstuttgart/typeinference/unify/TypeUnifyTask.java
+++ b/src/main/java/de/dhbwstuttgart/typeinference/unify/TypeUnifyTask.java
@@ -641,7 +641,9 @@ public class TypeUnifyTask extends RecursiveTask<Set<Set<UnifyPair>>>  {
 				 			  			 x.getPairOp() == PairOperator.EQUALSDOT)
 				 			  	 .map(x -> ((PlaceholderType)x.getGroundBasePair().getLhsType()).getVariance())
 				 			  	 .findAny();
-			variance = optVariance.isPresent() ? optVariance.get() : 2;		  
+			//Fuer Operatorenaufrufe wird variance auf 2 gesetzt
+			//Es werden alle Elemente des Kartesischen Produkts abgearbeitet
+			variance = optVariance.isPresent() ? optVariance.get() : 2;
 		}
 
 		//if (variance == 1 && nextSetasList.size() > 1) {