diff --git a/src/de/dhbwstuttgart/typeinference/unify/model/ExtendsType.java b/src/de/dhbwstuttgart/typeinference/unify/model/ExtendsType.java
index d5490e96..13049c88 100644
--- a/src/de/dhbwstuttgart/typeinference/unify/model/ExtendsType.java
+++ b/src/de/dhbwstuttgart/typeinference/unify/model/ExtendsType.java
@@ -14,7 +14,7 @@ public final class ExtendsType extends WildcardType {
 	 * @param extendedType The extended type e.g. Integer in "? extends Integer"
 	 */
 	public ExtendsType(UnifyType extendedType) {
-		super("? extends " + extendedType.getName(), extendedType);
+		super("? extends " + extendedType.getName(), extendedType); 
 	}
 
 	/**
@@ -44,7 +44,10 @@ public final class ExtendsType extends WildcardType {
 
 	@Override
 	UnifyType apply(Unifier unif) {
-		return new ExtendsType(wildcardedType.apply(unif));
+		UnifyType newType = wildcardedType.apply(unif);
+		/*if(newType.hashCode() == wildcardedType.hashCode() && newType.equals(wildcardedType))
+			return this; // Reduced the amount of objects created*/
+		return new ExtendsType(newType);
 	}
 	
 	@Override
@@ -61,7 +64,12 @@ public final class ExtendsType extends WildcardType {
 		if(!(obj instanceof ExtendsType))
 			return false;
 		
+		if(obj.hashCode() != this.hashCode())
+			return false;
+	
 		ExtendsType other = (ExtendsType) obj;
+		
+	
 		return other.getWildcardedType().equals(wildcardedType);
 	}
 	
diff --git a/src/de/dhbwstuttgart/typeinference/unify/model/FiniteClosure.java b/src/de/dhbwstuttgart/typeinference/unify/model/FiniteClosure.java
index ac0862cc..a08f79cb 100644
--- a/src/de/dhbwstuttgart/typeinference/unify/model/FiniteClosure.java
+++ b/src/de/dhbwstuttgart/typeinference/unify/model/FiniteClosure.java
@@ -33,7 +33,6 @@ public class FiniteClosure implements IFiniteClosure {
 	 */
 	private Set<UnifyPair> pairs;
 	
-	//TODO Prüfen: Typen ohne Kante im Graph als extra Menge im Konstruktor mitgeben?
 	/**
 	 * Creates a new instance using the inheritance tree defined in the pairs.
 	 */
diff --git a/src/de/dhbwstuttgart/typeinference/unify/model/FunNType.java b/src/de/dhbwstuttgart/typeinference/unify/model/FunNType.java
index 94ac1cf8..31517891 100644
--- a/src/de/dhbwstuttgart/typeinference/unify/model/FunNType.java
+++ b/src/de/dhbwstuttgart/typeinference/unify/model/FunNType.java
@@ -58,7 +58,11 @@ public class FunNType extends UnifyType {
 	UnifyType apply(Unifier unif) {
 		// TODO this bypasses the validation of the type parameters.
 		// Wildcard types can be unified into FunNTypes.
-		return new FunNType(typeParams.apply(unif));
+		TypeParams newParams = typeParams.apply(unif);
+		/*if(newParams.hashCode() == typeParams.hashCode() && newParams.equals(typeParams))
+			return this;*/
+		
+		return new FunNType(newParams);
 	}
 
 	@Override
@@ -71,8 +75,11 @@ public class FunNType extends UnifyType {
 		if(!(obj instanceof FunNType))
 			return false;
 		
-		FunNType other = (FunNType) obj;
+		if(obj.hashCode() != this.hashCode())
+			return false;
 		
+		FunNType other = (FunNType) obj;
+
 		return other.getTypeParams().equals(typeParams);
 	}
 	
diff --git a/src/de/dhbwstuttgart/typeinference/unify/model/ReferenceType.java b/src/de/dhbwstuttgart/typeinference/unify/model/ReferenceType.java
index ad02c9ab..9ffea796 100644
--- a/src/de/dhbwstuttgart/typeinference/unify/model/ReferenceType.java
+++ b/src/de/dhbwstuttgart/typeinference/unify/model/ReferenceType.java
@@ -11,12 +11,19 @@ import de.dhbwstuttgart.typeinference.unify.interfaces.IFiniteClosure;
  */
 public final class ReferenceType extends UnifyType {
 	
-	public ReferenceType(String name, UnifyType... typeParams) {
-		super(name, new TypeParams(typeParams));
+	/**
+	 * The buffered hashCode
+	 */
+	private final int hashCode;
+	
+	public ReferenceType(String name, UnifyType... params) {
+		super(name, new TypeParams(params));
+		hashCode = 31 + 17 * typeName.hashCode() + 17 * typeParams.hashCode();
 	}
 	
 	public ReferenceType(String name, TypeParams params) {
 		super(name, params);
+		hashCode = 31 + 17 * typeName.hashCode() + 17 * typeParams.hashCode();
 	}
 
 	@Override
@@ -31,17 +38,24 @@ public final class ReferenceType extends UnifyType {
 
 	@Override
 	UnifyType apply(Unifier unif) {
-		return new ReferenceType(typeName, typeParams.apply(unif));
+		TypeParams newParams = typeParams.apply(unif);
+		
+		/*if(newParams.hashCode() == typeParams.hashCode() && newParams.equals(typeParams))
+			return this;*/
+		
+		return new ReferenceType(new String(typeName), newParams);
 	}
 	
 	@Override
 	public UnifyType setTypeParams(TypeParams newTp) {
+		/*if(newTp.hashCode() == typeParams.hashCode() && newTp.equals(typeParams))
+			return this; // reduced the amount of objects created*/
 		return new ReferenceType(new String(typeName), newTp);
 	}
 	
 	@Override
 	public int hashCode() {
-		return 31 + 17 * typeName.hashCode() + 17 * typeParams.hashCode();
+		return hashCode;
 	}
 	
 	@Override
@@ -49,6 +63,9 @@ public final class ReferenceType extends UnifyType {
 		if(!(obj instanceof ReferenceType))
 			return false;
 		
+		if(obj.hashCode() != this.hashCode())
+			return false;
+		
 		ReferenceType other = (ReferenceType) obj;
 		
 		if(!other.getName().equals(typeName))
diff --git a/src/de/dhbwstuttgart/typeinference/unify/model/SuperType.java b/src/de/dhbwstuttgart/typeinference/unify/model/SuperType.java
index 8a828156..664e1624 100644
--- a/src/de/dhbwstuttgart/typeinference/unify/model/SuperType.java
+++ b/src/de/dhbwstuttgart/typeinference/unify/model/SuperType.java
@@ -50,7 +50,10 @@ public final class SuperType extends WildcardType {
 	
 	@Override
 	UnifyType apply(Unifier unif) {
-		return new SuperType(wildcardedType.apply(unif));
+		UnifyType newType = wildcardedType.apply(unif);
+		/*if(newType.hashCode() == wildcardedType.hashCode() && newType.equals(wildcardedType))
+			return this; // Reduced the amount of objects created*/
+		return new SuperType(newType);
 	}
 	
 	@Override
@@ -67,6 +70,9 @@ public final class SuperType extends WildcardType {
 		if(!(obj instanceof SuperType))
 			return false;
 		
+		if(obj.hashCode() != this.hashCode())
+			return false;
+		
 		SuperType other = (SuperType) obj;
 		return other.getSuperedType().equals(wildcardedType);
 	}
diff --git a/src/de/dhbwstuttgart/typeinference/unify/model/TypeParams.java b/src/de/dhbwstuttgart/typeinference/unify/model/TypeParams.java
index 7ce251d9..f2336e96 100644
--- a/src/de/dhbwstuttgart/typeinference/unify/model/TypeParams.java
+++ b/src/de/dhbwstuttgart/typeinference/unify/model/TypeParams.java
@@ -39,7 +39,7 @@ public final class TypeParams implements Iterable<UnifyType>{
 	 */
 	public TypeParams(UnifyType... types) {
 		typeParams = types;
-		
+	
 		// Hashcode calculation is expensive and must be cached.
 		hashCode = Arrays.hashCode(typeParams);
 	}
@@ -73,8 +73,22 @@ public final class TypeParams implements Iterable<UnifyType>{
 	 */
 	public TypeParams apply(Unifier unif) {
 		UnifyType[] newParams = new UnifyType[typeParams.length];
-		for(int i = 0; i < typeParams.length; i++)
-			newParams[i] = typeParams[i].apply(unif);
+		
+		// If true, a type was modified and a new typeparams object has to be created.
+		// Otherwise it is enough to return this object, since it is immutable
+		// This reduced the needed TypeParams-Instances for the lambda14-Test from
+		// 130.000 to 30.000 without a decrease in speed.
+		boolean isNew = false; 
+		
+		for(int i = 0; i < typeParams.length; i++) {
+			UnifyType newType = typeParams[i].apply(unif);
+			newParams[i] = newType;
+			//if(!isNew && (newType.hashCode() != typeParams[i].hashCode() || !newType.equals(typeParams[i])))
+				//isNew = true;
+		}
+		
+		//if(!isNew)
+		//	return this;
 		return new TypeParams(newParams);
 	}
 	
@@ -107,8 +121,13 @@ public final class TypeParams implements Iterable<UnifyType>{
 	 * @throws ArrayOutOfBoundsException if i > this.size()-1.
 	 */
 	public TypeParams set(UnifyType t, int idx) {
+		// Reduce the creation of new objects for less memory 
+		// Reduced the needed instances of TypeParams in the lambda14-Test from
+		// 150.000 to 130.000
+		/*if(t.hashCode() == typeParams[idx].hashCode() && t.equals(typeParams[idx]))
+			return this;*/
 		UnifyType[] newparams = Arrays.copyOf(typeParams, typeParams.length);
-		newparams[idx] = t;
+		newparams[idx] = t; 
 		return new TypeParams(newparams);
 	}
 
@@ -127,6 +146,9 @@ public final class TypeParams implements Iterable<UnifyType>{
 		if(!(obj instanceof TypeParams))
 			return false;
 		
+		if(obj.hashCode() != this.hashCode())
+			return false;
+		
 		TypeParams other = (TypeParams) obj;
 		
 		if(other.size() != this.size())
diff --git a/src/de/dhbwstuttgart/typeinference/unify/model/UnifyPair.java b/src/de/dhbwstuttgart/typeinference/unify/model/UnifyPair.java
index 62de0c96..672a516d 100644
--- a/src/de/dhbwstuttgart/typeinference/unify/model/UnifyPair.java
+++ b/src/de/dhbwstuttgart/typeinference/unify/model/UnifyPair.java
@@ -63,6 +63,9 @@ public class UnifyPair {
 	public boolean equals(Object obj) {
 		if(!(obj instanceof UnifyPair))
 			return false;
+		
+		if(obj.hashCode() != this.hashCode())
+			return false;
 
 		UnifyPair other = (UnifyPair) obj;
 		
diff --git a/src/de/dhbwstuttgart/typeinference/unify/model/WildcardType.java b/src/de/dhbwstuttgart/typeinference/unify/model/WildcardType.java
index 19efd88a..9b42c087 100644
--- a/src/de/dhbwstuttgart/typeinference/unify/model/WildcardType.java
+++ b/src/de/dhbwstuttgart/typeinference/unify/model/WildcardType.java
@@ -47,6 +47,9 @@ public abstract class WildcardType extends UnifyType {
 		if(!(obj instanceof WildcardType))
 			return false;
 		
+		if(obj.hashCode() != this.hashCode())
+			return false;
+		
 		WildcardType other = (WildcardType) obj;
 		return other.getWildcardedType().equals(wildcardedType);
 	}